diff --git a/any-by-right/benchmark/benchmark.js b/any-by-right/benchmark/benchmark.js
index e647539d..b71d57e2 100644
--- a/any-by-right/benchmark/benchmark.js
+++ b/any-by-right/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ NaN, i, i+1, i+2, i+3, i+4 ];
 		bool = anyByRight( arr, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -67,7 +67,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4, NaN ];
 		bool = arr.some( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -95,8 +95,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/any-by/benchmark/benchmark.js b/any-by/benchmark/benchmark.js
index f06445b4..fbc78c51 100644
--- a/any-by/benchmark/benchmark.js
+++ b/any-by/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4, NaN ];
 		bool = anyBy( arr, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -67,7 +67,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4, NaN ];
 		bool = arr.some( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -95,8 +95,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/any/benchmark/benchmark.js b/any/benchmark/benchmark.js
index ea9627ce..d92e67dc 100644
--- a/any/benchmark/benchmark.js
+++ b/any/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 0, 0, 0, 0, 0, i ];
 		bool = any( arr );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -62,7 +62,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 0, 0, 0, 0, 0, 1 ];
 		bool = arr.some( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -90,7 +90,7 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should be a boolean' );
 		}
 	}
diff --git a/bifurcate-by/benchmark/benchmark.js b/bifurcate-by/benchmark/benchmark.js
index 6e2684ad..2ba0bbac 100644
--- a/bifurcate-by/benchmark/benchmark.js
+++ b/bifurcate-by/benchmark/benchmark.js
@@ -55,7 +55,7 @@ bench( pkg, function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		o = bifurcateBy( arr, predicate );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -96,7 +96,7 @@ bench( pkg+'::values', function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		o = bifurcateBy( arr, opts, predicate );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -137,7 +137,7 @@ bench( pkg+'::indices', function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		o = bifurcateBy( arr, opts, predicate );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -178,7 +178,7 @@ bench( pkg+'::pairs', function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		o = bifurcateBy( arr, opts, predicate );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -219,7 +219,7 @@ bench( pkg+'::this_context', function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		o = bifurcateBy( arr, opts, predicate );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/bifurcate/benchmark/benchmark.js b/bifurcate/benchmark/benchmark.js
index eb72b035..ccaf6945 100644
--- a/bifurcate/benchmark/benchmark.js
+++ b/bifurcate/benchmark/benchmark.js
@@ -55,7 +55,7 @@ bench( pkg, function benchmark( b ) {
 			filter[ j ] = ( randu() < 0.5 );
 		}
 		o = bifurcate( arr, filter );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -96,7 +96,7 @@ bench( pkg+'::values', function benchmark( b ) {
 			filter[ j ] = ( randu() < 0.5 );
 		}
 		o = bifurcate( arr, opts, filter );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -137,7 +137,7 @@ bench( pkg+'::indices', function benchmark( b ) {
 			filter[ j ] = ( randu() < 0.5 );
 		}
 		o = bifurcate( arr, opts, filter );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -178,7 +178,7 @@ bench( pkg+'::pairs', function benchmark( b ) {
 			filter[ j ] = ( randu() < 0.5 );
 		}
 		o = bifurcate( arr, opts, filter );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/common-keys-in/docs/types/test.ts b/common-keys-in/docs/types/test.ts
index 918e96c2..63cb933f 100644
--- a/common-keys-in/docs/types/test.ts
+++ b/common-keys-in/docs/types/test.ts
@@ -26,7 +26,7 @@ import commonKeysIn = require( './index' );
 	commonKeysIn( { 'a': 0, 'b': 1 }, { 'a': 0 } ); // $ExpectType string[]
 }
 
-// The function does not compile if provided insufficient arguments...
+// The compiler throws an error if the function is provided insufficient arguments...
 {
 	commonKeysIn(); // $ExpectError
 	commonKeysIn( {} ); // $ExpectError
diff --git a/common-keys/docs/types/test.ts b/common-keys/docs/types/test.ts
index bf5144bc..93f55bb4 100644
--- a/common-keys/docs/types/test.ts
+++ b/common-keys/docs/types/test.ts
@@ -26,7 +26,7 @@ import commonKeys = require( './index' );
 	commonKeys( { 'a': 0, 'b': 1 }, { 'a': 0 } ); // $ExpectType string[]
 }
 
-// The function does not compile if provided insufficient arguments...
+// The compiler throws an error if the function is provided insufficient arguments...
 {
 	commonKeys(); // $ExpectError
 	commonKeys( {} ); // $ExpectError
diff --git a/constructor-name/benchmark/benchmark.js b/constructor-name/benchmark/benchmark.js
index 272071e0..537d43d2 100644
--- a/constructor-name/benchmark/benchmark.js
+++ b/constructor-name/benchmark/benchmark.js
@@ -87,7 +87,7 @@ bench( pkg, function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( values[ i%values.length ] );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -109,7 +109,7 @@ bench( pkg+'::array', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -131,7 +131,7 @@ bench( pkg+'::typed_array', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -153,7 +153,7 @@ bench( pkg+'::buffer', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -175,7 +175,7 @@ bench( pkg+'::error', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -197,7 +197,7 @@ bench( pkg+'::date', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -219,7 +219,7 @@ bench( pkg+'::string', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -241,7 +241,7 @@ bench( pkg+'::number', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -263,7 +263,7 @@ bench( pkg+'::boolean', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -285,7 +285,7 @@ bench( pkg+'::null', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -307,7 +307,7 @@ bench( pkg+'::object', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -329,7 +329,7 @@ bench( pkg+'::regexp', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
@@ -351,7 +351,7 @@ bench( pkg+'::function', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = constructorName( v );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/convert-path/docs/types/test.ts b/convert-path/docs/types/test.ts
index 28ecb398..d4c236f6 100644
--- a/convert-path/docs/types/test.ts
+++ b/convert-path/docs/types/test.ts
@@ -28,7 +28,7 @@ import convertPath = require( './index' );
 	convertPath( 'C:\\foo\\bar\\beep.c', 'posix' ); // $ExpectType string
 }
 
-// The function does not compile if provided arguments having invalid types...
+// The compiler throws an error if the function is provided arguments having invalid types...
 {
 	convertPath( true, 'win32' ); // $ExpectError
 	convertPath( false, 'win32' ); // $ExpectError
@@ -45,7 +45,7 @@ import convertPath = require( './index' );
 	convertPath( '/c/foo/bar/beep.c', ( x: number ): number => x ); // $ExpectError
 }
 
-// The function does not compile if provided insufficient arguments...
+// The compiler throws an error if the function is provided insufficient arguments...
 {
 	convertPath(); // $ExpectError
 	convertPath( 'abc' ); // $ExpectError
diff --git a/define-configurable-read-only-accessor/benchmark/benchmark.js b/define-configurable-read-only-accessor/benchmark/benchmark.js
index 30df0030..a078c25c 100644
--- a/define-configurable-read-only-accessor/benchmark/benchmark.js
+++ b/define-configurable-read-only-accessor/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setConfigurableReadOnlyAccessor( obj, 'foo', getter( i ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-configurable-read-only-property/benchmark/benchmark.js b/define-configurable-read-only-property/benchmark/benchmark.js
index 08d960ed..e8c73f93 100644
--- a/define-configurable-read-only-property/benchmark/benchmark.js
+++ b/define-configurable-read-only-property/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setConfigurableReadOnly( obj, 'foo', fromCodePoint( 97 + (i%26) ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-configurable-read-write-accessor/benchmark/benchmark.js b/define-configurable-read-write-accessor/benchmark/benchmark.js
index 20ec386a..a2db4962 100644
--- a/define-configurable-read-write-accessor/benchmark/benchmark.js
+++ b/define-configurable-read-write-accessor/benchmark/benchmark.js
@@ -36,7 +36,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setConfigurableReadWriteAccessor( obj, 'foo', getter( i.toString() ), setter );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-memoized-configurable-read-only-property/benchmark/benchmark.js b/define-memoized-configurable-read-only-property/benchmark/benchmark.js
index 41b3408e..46f6f607 100644
--- a/define-memoized-configurable-read-only-property/benchmark/benchmark.js
+++ b/define-memoized-configurable-read-only-property/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setMemoizedConfigurableReadOnly( obj, 'foo', f( i ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-memoized-property/benchmark/benchmark.js b/define-memoized-property/benchmark/benchmark.js
index ec7d16cc..e4740c4f 100644
--- a/define-memoized-property/benchmark/benchmark.js
+++ b/define-memoized-property/benchmark/benchmark.js
@@ -41,7 +41,7 @@ bench( pkg, function benchmark( b ) {
 		obj = {};
 		descriptor.value = f( i );
 		defineMemoizedProperty( obj, 'foo', descriptor );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-memoized-read-only-property/benchmark/benchmark.js b/define-memoized-read-only-property/benchmark/benchmark.js
index ecc5cedf..3ed1ad0b 100644
--- a/define-memoized-read-only-property/benchmark/benchmark.js
+++ b/define-memoized-read-only-property/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setMemoizedReadOnly( obj, 'foo', f( i ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-nonenumerable-property/benchmark/benchmark.js b/define-nonenumerable-property/benchmark/benchmark.js
index 31268d30..1967dbf5 100644
--- a/define-nonenumerable-property/benchmark/benchmark.js
+++ b/define-nonenumerable-property/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setNonEnumerableProperty( obj, 'foo', fromCodePoint( 97 + (i%26) ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-nonenumerable-read-only-accessor/benchmark/benchmark.js b/define-nonenumerable-read-only-accessor/benchmark/benchmark.js
index 3a7dc2e3..165ce480 100644
--- a/define-nonenumerable-read-only-accessor/benchmark/benchmark.js
+++ b/define-nonenumerable-read-only-accessor/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setNonEnumerableReadOnlyAccessor( obj, 'foo', getter( i ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-nonenumerable-read-only-property/benchmark/benchmark.js b/define-nonenumerable-read-only-property/benchmark/benchmark.js
index 45a480c9..9c5cecce 100644
--- a/define-nonenumerable-read-only-property/benchmark/benchmark.js
+++ b/define-nonenumerable-read-only-property/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setNonEnumerableReadOnly( obj, 'foo', fromCodePoint( 97 + (i%26) ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-nonenumerable-read-write-accessor/benchmark/benchmark.js b/define-nonenumerable-read-write-accessor/benchmark/benchmark.js
index 8fb29c70..9569f18b 100644
--- a/define-nonenumerable-read-write-accessor/benchmark/benchmark.js
+++ b/define-nonenumerable-read-write-accessor/benchmark/benchmark.js
@@ -36,7 +36,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setNonEnumerableReadWriteAccessor( obj, 'foo', getter( i.toString() ), setter );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-properties/benchmark/benchmark.js b/define-properties/benchmark/benchmark.js
index 15570a40..3750a8ec 100644
--- a/define-properties/benchmark/benchmark.js
+++ b/define-properties/benchmark/benchmark.js
@@ -46,7 +46,7 @@ bench( pkg, function benchmark( b ) {
 		obj = {};
 		descriptors.foo.value = fromCodePoint( 97 + (i%26) );
 		defineProperties( obj, descriptors );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-property/benchmark/benchmark.js b/define-property/benchmark/benchmark.js
index af59859b..23bf91a8 100644
--- a/define-property/benchmark/benchmark.js
+++ b/define-property/benchmark/benchmark.js
@@ -40,7 +40,7 @@ bench( pkg, function benchmark( b ) {
 		obj = {};
 		descriptor.value = fromCodePoint( 97 + (i%26) );
 		defineProperty( obj, 'foo', descriptor );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-read-only-accessor/benchmark/benchmark.js b/define-read-only-accessor/benchmark/benchmark.js
index 522b30d0..062e64c6 100644
--- a/define-read-only-accessor/benchmark/benchmark.js
+++ b/define-read-only-accessor/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setReadOnlyAccessor( obj, 'foo', getter( i ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-read-only-property/benchmark/benchmark.js b/define-read-only-property/benchmark/benchmark.js
index 3cc769c4..553e24ac 100644
--- a/define-read-only-property/benchmark/benchmark.js
+++ b/define-read-only-property/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setReadOnly( obj, 'foo', fromCodePoint( 97 + (i%26) ) );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/define-read-write-accessor/benchmark/benchmark.js b/define-read-write-accessor/benchmark/benchmark.js
index 98bc79bf..c1fee0d7 100644
--- a/define-read-write-accessor/benchmark/benchmark.js
+++ b/define-read-write-accessor/benchmark/benchmark.js
@@ -36,7 +36,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj = {};
 		setReadWriteAccessor( obj, 'foo', getter( i.toString() ), setter );
-		if ( !isString( obj.foo ) ) {
+		if ( typeof obj.foo !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/dirname/docs/types/test.ts b/dirname/docs/types/test.ts
index fb01b26c..2cb236f2 100644
--- a/dirname/docs/types/test.ts
+++ b/dirname/docs/types/test.ts
@@ -26,7 +26,7 @@ import dirname = require( './index' );
 	dirname( './foo/bar/index.js' ); // $ExpectType string
 }
 
-// The function does not compile if provided a value other than a string...
+// The compiler throws an error if the function is provided a value other than a string...
 {
 	dirname( true ); // $ExpectError
 	dirname( false ); // $ExpectError
diff --git a/do-until/docs/types/test.ts b/do-until/docs/types/test.ts
index 3391986c..e24f5621 100644
--- a/do-until/docs/types/test.ts
+++ b/do-until/docs/types/test.ts
@@ -64,7 +64,7 @@ function noop() {
 	doUntil( noop, {} ); // $ExpectError
 }
 
-// The function does not compile if provided fewer than two arguments...
+// The compiler throws an error if the function is provided fewer than two arguments...
 {
 	doUntil(); // $ExpectError
 	doUntil( noop ); // $ExpectError
diff --git a/do-while/docs/types/test.ts b/do-while/docs/types/test.ts
index 0f92a720..8f32300b 100644
--- a/do-while/docs/types/test.ts
+++ b/do-while/docs/types/test.ts
@@ -64,7 +64,7 @@ function noop() {
 	doWhile( noop, {} ); // $ExpectError
 }
 
-// The function does not compile if provided fewer than two arguments...
+// The compiler throws an error if the function is provided fewer than two arguments...
 {
 	doWhile(); // $ExpectError
 	doWhile( noop ); // $ExpectError
diff --git a/entries-in/benchmark/benchmark.js b/entries-in/benchmark/benchmark.js
index b63d6665..5a1b2957 100644
--- a/entries-in/benchmark/benchmark.js
+++ b/entries-in/benchmark/benchmark.js
@@ -52,7 +52,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = objectEntriesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/entries/benchmark/benchmark.js b/entries/benchmark/benchmark.js
index 607136dd..ada091c6 100644
--- a/entries/benchmark/benchmark.js
+++ b/entries/benchmark/benchmark.js
@@ -47,7 +47,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = objectEntries( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/enumerable-properties-in/benchmark/benchmark.js b/enumerable-properties-in/benchmark/benchmark.js
index 91de28f0..f3647fc9 100644
--- a/enumerable-properties-in/benchmark/benchmark.js
+++ b/enumerable-properties-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = enumerablePropertiesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/enumerable-properties/benchmark/benchmark.js b/enumerable-properties/benchmark/benchmark.js
index 01ec1d61..be3d5a34 100644
--- a/enumerable-properties/benchmark/benchmark.js
+++ b/enumerable-properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = enumerableProperties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/enumerable-property-symbols-in/benchmark/benchmark.js b/enumerable-property-symbols-in/benchmark/benchmark.js
index 138dced6..bd22db48 100644
--- a/enumerable-property-symbols-in/benchmark/benchmark.js
+++ b/enumerable-property-symbols-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = enumerablePropertySymbolsIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/enumerable-property-symbols/benchmark/benchmark.js b/enumerable-property-symbols/benchmark/benchmark.js
index 9f705439..5efcd9d4 100644
--- a/enumerable-property-symbols/benchmark/benchmark.js
+++ b/enumerable-property-symbols/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = enumerablePropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/escape-regexp-string/benchmark/benchmark.js b/escape-regexp-string/benchmark/benchmark.js
index fd7e6068..baf82cf2 100644
--- a/escape-regexp-string/benchmark/benchmark.js
+++ b/escape-regexp-string/benchmark/benchmark.js
@@ -45,7 +45,7 @@ bench( pkg, function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = rescape( values[ i % values.length ] );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/every-by-right/benchmark/benchmark.js b/every-by-right/benchmark/benchmark.js
index 0da402c0..a0516595 100644
--- a/every-by-right/benchmark/benchmark.js
+++ b/every-by-right/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = everyByRight( arr, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -67,7 +67,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = arr.every( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -95,8 +95,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/every-by/benchmark/benchmark.js b/every-by/benchmark/benchmark.js
index 7a892706..4fe6a87f 100644
--- a/every-by/benchmark/benchmark.js
+++ b/every-by/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = everyBy( arr, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -67,7 +67,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = arr.every( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -95,8 +95,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/every/benchmark/benchmark.js b/every/benchmark/benchmark.js
index 2eda163f..032a6d3b 100644
--- a/every/benchmark/benchmark.js
+++ b/every/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i+1, i+2, i+3, i+4, i+5, 0 ];
 		bool = every( arr );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -62,7 +62,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i+1, i+2, i+3, i+4, i+5, 0 ];
 		bool = arr.every( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -90,8 +90,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/extname/docs/types/test.ts b/extname/docs/types/test.ts
index b11b1188..79a7f924 100644
--- a/extname/docs/types/test.ts
+++ b/extname/docs/types/test.ts
@@ -26,7 +26,7 @@ import extname = require( './index' );
 	extname( 'index.js' ); // $ExpectType string
 }
 
-// The function does not compile if provided a value other than a string...
+// The compiler throws an error if the function is provided a value other than a string...
 {
 	extname( true ); // $ExpectError
 	extname( false ); // $ExpectError
diff --git a/flatten-array/benchmark/benchmark.copy.js b/flatten-array/benchmark/benchmark.copy.js
index de507cf2..f7fb54a3 100644
--- a/flatten-array/benchmark/benchmark.copy.js
+++ b/flatten-array/benchmark/benchmark.copy.js
@@ -42,7 +42,7 @@ bench( pkg+':copy=true', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 1, [2, [3, [4, [ 5 ], 6], 7], 8], 9 ];
 		out = flattenArray( arr, opts );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/flatten-array/benchmark/benchmark.depth.js b/flatten-array/benchmark/benchmark.depth.js
index 820c7d20..b229bb7b 100644
--- a/flatten-array/benchmark/benchmark.depth.js
+++ b/flatten-array/benchmark/benchmark.depth.js
@@ -41,7 +41,7 @@ bench( pkg+':depth=2', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 1, [2, [3, [4, [ 5 ], 6], 7], 8], 9 ];
 		out = flattenArray( arr, opts );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/flatten-array/benchmark/benchmark.factory.js b/flatten-array/benchmark/benchmark.factory.js
index 4c6349f4..ede4e4d5 100644
--- a/flatten-array/benchmark/benchmark.factory.js
+++ b/flatten-array/benchmark/benchmark.factory.js
@@ -44,7 +44,7 @@ bench( pkg+':factory', function benchmark( b ) {
 			[ 7, 8, 9 ]
 		];
 		out = flatten( arr );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/flatten-array/benchmark/benchmark.factory_copy.js b/flatten-array/benchmark/benchmark.factory_copy.js
index c2bd746b..11e37ca1 100644
--- a/flatten-array/benchmark/benchmark.factory_copy.js
+++ b/flatten-array/benchmark/benchmark.factory_copy.js
@@ -50,7 +50,7 @@ bench( pkg+':factory:copy=true', function benchmark( b ) {
 			[ 7, 8, 9 ]
 		];
 		out = flatten( arr );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/flatten-array/benchmark/benchmark.js b/flatten-array/benchmark/benchmark.js
index 4efd5e55..255ff869 100644
--- a/flatten-array/benchmark/benchmark.js
+++ b/flatten-array/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 1, [2, [3, [4, [ 5 ], 6], 7], 8], 9 ];
 		out = flattenArray( arr );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/flatten-array/benchmark/benchmark.large_arrays.js b/flatten-array/benchmark/benchmark.large_arrays.js
index f1fff397..7b027308 100644
--- a/flatten-array/benchmark/benchmark.large_arrays.js
+++ b/flatten-array/benchmark/benchmark.large_arrays.js
@@ -60,7 +60,7 @@ bench( pkg+'::large_arrays', function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		out = flattenArray( data );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/function-name/benchmark/benchmark.js b/function-name/benchmark/benchmark.js
index 2c39fafe..69ac4baf 100644
--- a/function-name/benchmark/benchmark.js
+++ b/function-name/benchmark/benchmark.js
@@ -75,7 +75,7 @@ bench( pkg, function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = functionName( values[ i%values.length ] );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/function-name/docs/types/test.ts b/function-name/docs/types/test.ts
index 9b61e764..f2481aaf 100644
--- a/function-name/docs/types/test.ts
+++ b/function-name/docs/types/test.ts
@@ -26,7 +26,7 @@ import functionName = require( './index' );
 	functionName( String ); // $ExpectType string
 }
 
-// The function does not compile if provided a value other than a function...
+// The compiler throws an error if the function is provided a value other than a function...
 {
 	functionName( true ); // $ExpectError
 	functionName( false ); // $ExpectError
@@ -36,7 +36,7 @@ import functionName = require( './index' );
 	functionName( 'abc' ); // $ExpectError
 }
 
-// The function does not compile if provided insufficient arguments...
+// The compiler throws an error if the function is provided insufficient arguments...
 {
 	functionName(); // $ExpectError
 }
diff --git a/index-of/docs/types/test.ts b/index-of/docs/types/test.ts
index 36dc858e..0b20932a 100644
--- a/index-of/docs/types/test.ts
+++ b/index-of/docs/types/test.ts
@@ -47,7 +47,7 @@ import indexOf = require( './index' );
 	indexOf( arr, 2, ( x: number ): number => x ); // $ExpectError
 }
 
-// The function does not compile if provided an invalid number of arguments...
+// The compiler throws an error if the function is provided an invalid number of arguments...
 {
 	const arr = [ 1, 2, 3, 4, 5, 2, 6 ];
 	indexOf(); // $ExpectError
diff --git a/inherited-enumerable-properties/benchmark/benchmark.js b/inherited-enumerable-properties/benchmark/benchmark.js
index 2cbf977e..9894414f 100644
--- a/inherited-enumerable-properties/benchmark/benchmark.js
+++ b/inherited-enumerable-properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedEnumerableProperties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-enumerable-property-symbols/benchmark/benchmark.js b/inherited-enumerable-property-symbols/benchmark/benchmark.js
index ff58301b..2f1f56eb 100644
--- a/inherited-enumerable-property-symbols/benchmark/benchmark.js
+++ b/inherited-enumerable-property-symbols/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedEnumerablePropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-keys/benchmark/benchmark.js b/inherited-keys/benchmark/benchmark.js
index 9a7e49c8..3c798c72 100644
--- a/inherited-keys/benchmark/benchmark.js
+++ b/inherited-keys/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedKeys( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-nonenumerable-properties/benchmark/benchmark.js b/inherited-nonenumerable-properties/benchmark/benchmark.js
index dd6ce85a..df254015 100644
--- a/inherited-nonenumerable-properties/benchmark/benchmark.js
+++ b/inherited-nonenumerable-properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedNonEnumerableProperties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-nonenumerable-property-names/benchmark/benchmark.js b/inherited-nonenumerable-property-names/benchmark/benchmark.js
index c8d491c7..baed0da7 100644
--- a/inherited-nonenumerable-property-names/benchmark/benchmark.js
+++ b/inherited-nonenumerable-property-names/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedNonEnumerablePropertyNames( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-nonenumerable-property-symbols/benchmark/benchmark.js b/inherited-nonenumerable-property-symbols/benchmark/benchmark.js
index 02950b0f..46bc6059 100644
--- a/inherited-nonenumerable-property-symbols/benchmark/benchmark.js
+++ b/inherited-nonenumerable-property-symbols/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedNonEnumerablePropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-properties/benchmark/benchmark.js b/inherited-properties/benchmark/benchmark.js
index cc9faf7a..a3b94547 100644
--- a/inherited-properties/benchmark/benchmark.js
+++ b/inherited-properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedProperties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-property-names/benchmark/benchmark.js b/inherited-property-names/benchmark/benchmark.js
index 6856a535..de4c9e88 100644
--- a/inherited-property-names/benchmark/benchmark.js
+++ b/inherited-property-names/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedPropertyNames( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-property-symbols/benchmark/benchmark.js b/inherited-property-symbols/benchmark/benchmark.js
index 590f3c13..3e3c7922 100644
--- a/inherited-property-symbols/benchmark/benchmark.js
+++ b/inherited-property-symbols/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedPropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-writable-properties/benchmark/benchmark.js b/inherited-writable-properties/benchmark/benchmark.js
index 1847099a..d84ee192 100644
--- a/inherited-writable-properties/benchmark/benchmark.js
+++ b/inherited-writable-properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedWritableProperties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-writable-property-names/benchmark/benchmark.js b/inherited-writable-property-names/benchmark/benchmark.js
index 7900c0c4..4e0e4c80 100644
--- a/inherited-writable-property-names/benchmark/benchmark.js
+++ b/inherited-writable-property-names/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedWritablePropertyNames( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/inherited-writable-property-symbols/benchmark/benchmark.js b/inherited-writable-property-symbols/benchmark/benchmark.js
index 4c8838ca..9b2ba657 100644
--- a/inherited-writable-property-symbols/benchmark/benchmark.js
+++ b/inherited-writable-property-symbols/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = inheritedWritablePropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/keys-in/benchmark/benchmark.js b/keys-in/benchmark/benchmark.js
index dfc78517..3ccd1902 100644
--- a/keys-in/benchmark/benchmark.js
+++ b/keys-in/benchmark/benchmark.js
@@ -52,7 +52,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = keysIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/keys-in/docs/types/test.ts b/keys-in/docs/types/test.ts
index 5391eb99..808989a6 100644
--- a/keys-in/docs/types/test.ts
+++ b/keys-in/docs/types/test.ts
@@ -26,7 +26,7 @@ import keysIn = require( './index' );
 	keysIn( { 'beep': 'boop', 'foo': 3.14 } ); // $ExpectType string[]
 }
 
-// The function does not compile if provided insufficient arguments...
+// The compiler throws an error if the function is provided insufficient arguments...
 {
 	keysIn(); // $ExpectError
 }
diff --git a/keys/benchmark/benchmark.js b/keys/benchmark/benchmark.js
index c6ab4a95..3b374d63 100644
--- a/keys/benchmark/benchmark.js
+++ b/keys/benchmark/benchmark.js
@@ -63,7 +63,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = keys( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -98,7 +98,7 @@ bench( pkg+'::polyfill', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = polyfill( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -133,7 +133,7 @@ bench( pkg+'::builtin', opts, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = Object.keys( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -168,7 +168,7 @@ bench( pkg+'::builtin_wrapper', opts, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = wrapper( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -203,7 +203,7 @@ bench( pkg+'::builtin_arguments_wrapper', opts, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = argsWrapper( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/keys/docs/types/test.ts b/keys/docs/types/test.ts
index a95bce74..f25c73c3 100644
--- a/keys/docs/types/test.ts
+++ b/keys/docs/types/test.ts
@@ -26,7 +26,7 @@ import keys = require( './index' );
 	keys( { 'beep': 'boop', 'foo': 3.14 } ); // $ExpectType string[]
 }
 
-// The function does not compile if provided insufficient arguments...
+// The compiler throws an error if the function is provided insufficient arguments...
 {
 	keys(); // $ExpectError
 }
diff --git a/map-function/docs/types/test.ts b/map-function/docs/types/test.ts
index f13bac70..2acab93f 100644
--- a/map-function/docs/types/test.ts
+++ b/map-function/docs/types/test.ts
@@ -54,7 +54,7 @@ function identity( x: any ): any {
 	mapFun( identity, {} ); // $ExpectError
 }
 
-// The function does not compile if provided fewer than two arguments...
+// The compiler throws an error if the function is provided fewer than two arguments...
 {
 	mapFun(); // $ExpectError
 	mapFun( identity ); // $ExpectError
diff --git a/native-class/benchmark/benchmark.js b/native-class/benchmark/benchmark.js
index 4b064540..daa77d90 100644
--- a/native-class/benchmark/benchmark.js
+++ b/native-class/benchmark/benchmark.js
@@ -51,7 +51,7 @@ bench( pkg, function benchmark( b ) {
 	b.tic();
 	for ( i = 0; i < b.iterations; i++ ) {
 		str = nativeClass( values[ i%values.length ] );
-		if ( !isString( str ) ) {
+		if ( typeof str !== 'string' ) {
 			b.fail( 'should return a string' );
 		}
 	}
diff --git a/none-by-right/benchmark/benchmark.js b/none-by-right/benchmark/benchmark.js
index a5397574..bbca404c 100644
--- a/none-by-right/benchmark/benchmark.js
+++ b/none-by-right/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = noneByRight( arr, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -67,7 +67,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = arr.every( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -95,7 +95,7 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should be a boolean' );
 		}
 	}
diff --git a/none-by/benchmark/benchmark.js b/none-by/benchmark/benchmark.js
index 765ae524..82def150 100644
--- a/none-by/benchmark/benchmark.js
+++ b/none-by/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = noneBy( arr, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -67,7 +67,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, i+3, i+4 ];
 		bool = arr.every( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -95,8 +95,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/none/benchmark/benchmark.js b/none/benchmark/benchmark.js
index e8916d33..1c1bde4d 100644
--- a/none/benchmark/benchmark.js
+++ b/none/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 0, 0, 0, 0, 0, i+1 ];
 		bool = none( arr );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -62,7 +62,7 @@ bench( pkg+'::built-in', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 0, 0, 0, 0, 0, i+1 ];
 		bool = arr.every( predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -90,8 +90,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				break;
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/nonenumerable-properties-in/benchmark/benchmark.js b/nonenumerable-properties-in/benchmark/benchmark.js
index d1abc606..0f4e13b4 100644
--- a/nonenumerable-properties-in/benchmark/benchmark.js
+++ b/nonenumerable-properties-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = nonEnumerablePropertiesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/nonenumerable-properties/benchmark/benchmark.js b/nonenumerable-properties/benchmark/benchmark.js
index 8e0af9c6..85823d24 100644
--- a/nonenumerable-properties/benchmark/benchmark.js
+++ b/nonenumerable-properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = nonEnumerableProperties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/nonenumerable-property-names-in/benchmark/benchmark.js b/nonenumerable-property-names-in/benchmark/benchmark.js
index ee271534..5130fae3 100644
--- a/nonenumerable-property-names-in/benchmark/benchmark.js
+++ b/nonenumerable-property-names-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = nonEnumerablePropertyNamesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/nonenumerable-property-names/benchmark/benchmark.js b/nonenumerable-property-names/benchmark/benchmark.js
index 991f4ee6..681a00c9 100644
--- a/nonenumerable-property-names/benchmark/benchmark.js
+++ b/nonenumerable-property-names/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = nonEnumerablePropertyNames( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/nonenumerable-property-symbols-in/benchmark/benchmark.js b/nonenumerable-property-symbols-in/benchmark/benchmark.js
index 5339f902..5c239c1a 100644
--- a/nonenumerable-property-symbols-in/benchmark/benchmark.js
+++ b/nonenumerable-property-symbols-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = nonEnumerablePropertySymbolsIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/nonenumerable-property-symbols/benchmark/benchmark.js b/nonenumerable-property-symbols/benchmark/benchmark.js
index 78488338..796fa392 100644
--- a/nonenumerable-property-symbols/benchmark/benchmark.js
+++ b/nonenumerable-property-symbols/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = nonEnumerablePropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/nonindex-keys/benchmark/benchmark.js b/nonindex-keys/benchmark/benchmark.js
index c85e9686..12401fad 100644
--- a/nonindex-keys/benchmark/benchmark.js
+++ b/nonindex-keys/benchmark/benchmark.js
@@ -52,7 +52,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = nonIndexKeys( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/nonindex-keys/docs/types/test.ts b/nonindex-keys/docs/types/test.ts
index b9d658e8..d5e5a5e6 100644
--- a/nonindex-keys/docs/types/test.ts
+++ b/nonindex-keys/docs/types/test.ts
@@ -26,7 +26,7 @@ import nonIndexKeys = require( './index' );
 	nonIndexKeys( { 'beep': 'boop', 'foo': 3.14 } ); // $ExpectType string[]
 }
 
-// The function does not compile if provided insufficient arguments...
+// The compiler throws an error if the function is provided insufficient arguments...
 {
 	nonIndexKeys(); // $ExpectError
 }
diff --git a/noop/benchmark/benchmark.js b/noop/benchmark/benchmark.js
index fed76888..4b714032 100644
--- a/noop/benchmark/benchmark.js
+++ b/noop/benchmark/benchmark.js
@@ -36,7 +36,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		// Note: the following *could* be optimized away via inlining and loop-invariant code motion. If so, the entire loop will disappear.
 		v = noop();
-		if ( !isUndefined( v ) ) {
+		if ( v !== void 0 ) {
 			b.fail( 'should return undefined' );
 		}
 	}
diff --git a/parse-json/docs/types/test.ts b/parse-json/docs/types/test.ts
index 53977d84..56e5ce46 100644
--- a/parse-json/docs/types/test.ts
+++ b/parse-json/docs/types/test.ts
@@ -48,7 +48,7 @@ import parseJSON = require( './index' );
 	parseJSON( '{"beep":"boop"}', 'baz' ); // $ExpectError
 }
 
-// The function does not compile if provided an unsupported number of arguments...
+// The compiler throws an error if the function is provided an unsupported number of arguments...
 {
 	parseJSON(); // $ExpectError
 	parseJSON( '{"beep":"boop"}', 'baz', 'boz' ); // $ExpectError
diff --git a/properties-in/benchmark/benchmark.js b/properties-in/benchmark/benchmark.js
index 1e67a5a5..1152c76d 100644
--- a/properties-in/benchmark/benchmark.js
+++ b/properties-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = propertiesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/properties/benchmark/benchmark.js b/properties/benchmark/benchmark.js
index 2c2a51cd..cdea9208 100644
--- a/properties/benchmark/benchmark.js
+++ b/properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = properties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/property-names-in/benchmark/benchmark.js b/property-names-in/benchmark/benchmark.js
index e95b83d4..f3afaa78 100644
--- a/property-names-in/benchmark/benchmark.js
+++ b/property-names-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = propertyNamesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/property-names/benchmark/benchmark.js b/property-names/benchmark/benchmark.js
index 5416ebac..a1596a85 100644
--- a/property-names/benchmark/benchmark.js
+++ b/property-names/benchmark/benchmark.js
@@ -68,7 +68,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = getOwnPropertyNames( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -109,7 +109,7 @@ bench( pkg+'::polyfill', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = polyfill( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -150,7 +150,7 @@ bench( pkg+'::builtin', opts, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = Object.getOwnPropertyNames( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/property-symbols-in/benchmark/benchmark.js b/property-symbols-in/benchmark/benchmark.js
index debc3da9..0820e420 100644
--- a/property-symbols-in/benchmark/benchmark.js
+++ b/property-symbols-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = propertySymbolsIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/property-symbols/benchmark/benchmark.js b/property-symbols/benchmark/benchmark.js
index b71c6be0..8a1af43e 100644
--- a/property-symbols/benchmark/benchmark.js
+++ b/property-symbols/benchmark/benchmark.js
@@ -68,7 +68,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = getOwnPropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -109,7 +109,7 @@ bench( pkg+'::polyfill', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = polyfill( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -150,7 +150,7 @@ bench( pkg+'::builtin', opts, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = Object.getOwnPropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/some-by-right/benchmark/benchmark.js b/some-by-right/benchmark/benchmark.js
index 8e43072e..4f976835 100644
--- a/some-by-right/benchmark/benchmark.js
+++ b/some-by-right/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ NaN, i, i+1, NaN, i+3, i+4 ];
 		bool = someByRight( arr, 2, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -78,8 +78,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				}
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/some-by/benchmark/benchmark.js b/some-by/benchmark/benchmark.js
index 70814998..8f7a2778 100644
--- a/some-by/benchmark/benchmark.js
+++ b/some-by/benchmark/benchmark.js
@@ -42,7 +42,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ i, i+1, i+2, NaN, i+4, NaN ];
 		bool = someBy( arr, 2, predicate );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -78,8 +78,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				}
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/some/benchmark/benchmark.js b/some/benchmark/benchmark.js
index 61dedd0a..dca7c0ed 100644
--- a/some/benchmark/benchmark.js
+++ b/some/benchmark/benchmark.js
@@ -37,7 +37,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr = [ 0, 0, i+1, i+2, i+3, i+4 ];
 		bool = some( arr, 4 );
-		if ( !isBoolean( bool ) ) {
+		if ( typeof bool !== 'boolean' ) {
 			b.fail( 'should return a boolean' );
 		}
 	}
@@ -73,8 +73,8 @@ bench( pkg+'::loop', function benchmark( b ) {
 				}
 			}
 		}
-		if ( !isBoolean( bool ) ) {
-			b.fail( 'should be a boolean' );
+		if ( typeof bool !== 'boolean' ) {
+			b.fail( 'should return a boolean' );
 		}
 	}
 	b.toc();
diff --git a/tabulate-by/benchmark/benchmark.js b/tabulate-by/benchmark/benchmark.js
index af17e94b..0b3ab302 100644
--- a/tabulate-by/benchmark/benchmark.js
+++ b/tabulate-by/benchmark/benchmark.js
@@ -55,7 +55,7 @@ bench( pkg, function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		out = tabulateBy( arr, indicator );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
@@ -96,7 +96,7 @@ bench( pkg+'::this_context', function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		out = tabulateBy( arr, opts, indicator );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/tabulate-by/benchmark/benchmark.length.js b/tabulate-by/benchmark/benchmark.length.js
index 5360047c..d61241ce 100644
--- a/tabulate-by/benchmark/benchmark.length.js
+++ b/tabulate-by/benchmark/benchmark.length.js
@@ -76,7 +76,7 @@ function createBenchmark( len ) {
 			j = floor( randu()*N );
 			x[ 0 ] = VALS[ j ];
 			out = tabulateBy( x, indicator );
-			if ( !isArray( out ) ) {
+			if ( typeof out !== 'object' ) {
 				b.fail( 'should return an array' );
 			}
 		}
diff --git a/tabulate-by/benchmark/benchmark.uniqueness.js b/tabulate-by/benchmark/benchmark.uniqueness.js
index d288553e..91057552 100644
--- a/tabulate-by/benchmark/benchmark.uniqueness.js
+++ b/tabulate-by/benchmark/benchmark.uniqueness.js
@@ -72,7 +72,7 @@ function createBenchmark( len, arr, N ) {
 			j = floor( randu()*N );
 			x[ 0 ] = arr[ j ];
 			out = tabulateBy( x, indicator );
-			if ( !isArray( out ) ) {
+			if ( typeof out !== 'object' ) {
 				b.fail( 'should return an array' );
 			}
 		}
diff --git a/tabulate/benchmark/benchmark.js b/tabulate/benchmark/benchmark.js
index 8db85009..ec5f4b49 100644
--- a/tabulate/benchmark/benchmark.js
+++ b/tabulate/benchmark/benchmark.js
@@ -51,7 +51,7 @@ bench( pkg, function benchmark( b ) {
 		j = floor( randu()*vals.length );
 		arr[ 0 ] = vals[ j ];
 		out = tabulate( arr );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/tabulate/benchmark/benchmark.length.js b/tabulate/benchmark/benchmark.length.js
index 4dbd8070..0d383b56 100644
--- a/tabulate/benchmark/benchmark.length.js
+++ b/tabulate/benchmark/benchmark.length.js
@@ -72,7 +72,7 @@ function createBenchmark( len ) {
 			j = floor( randu()*N );
 			x[ 0 ] = VALS[ j ];
 			out = tabulate( x );
-			if ( !isArray( out ) ) {
+			if ( typeof out !== 'object' ) {
 				b.fail( 'should return an array' );
 			}
 		}
diff --git a/tabulate/benchmark/benchmark.uniqueness.js b/tabulate/benchmark/benchmark.uniqueness.js
index 1c1f4d24..a0859fc3 100644
--- a/tabulate/benchmark/benchmark.uniqueness.js
+++ b/tabulate/benchmark/benchmark.uniqueness.js
@@ -68,7 +68,7 @@ function createBenchmark( len, arr, N ) {
 			j = floor( randu()*N );
 			x[ 0 ] = arr[ j ];
 			out = tabulate( x );
-			if ( !isArray( out ) ) {
+			if ( typeof out !== 'object' ) {
 				b.fail( 'should return an array' );
 			}
 		}
diff --git a/try-require/benchmark/benchmark.js b/try-require/benchmark/benchmark.js
index 58b3b5d6..a1cfb213 100644
--- a/try-require/benchmark/benchmark.js
+++ b/try-require/benchmark/benchmark.js
@@ -37,8 +37,8 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		path = ( i % 2 === 0 ) ? '@stdlib/assert/is-array' : './../lib';
 		out = tryRequire( path );
-		if ( !isFunction( out ) ) {
-			b.fail( 'should return function' );
+		if ( typeof out !== 'function' ) {
+			b.fail( 'should return a function' );
 		}
 	}
 	b.toc();
@@ -58,8 +58,8 @@ bench( pkg+'::require', function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		path = ( i % 2 === 0 ) ? '@stdlib/assert/is-array' : './../lib';
 		out = require( path ); // eslint-disable-line stdlib/no-dynamic-require
-		if ( !isFunction( out ) ) {
-			b.fail( 'should return function' );
+		if ( typeof out !== 'function' ) {
+			b.fail( 'should return a function' );
 		}
 	}
 	b.toc();
diff --git a/until/docs/types/test.ts b/until/docs/types/test.ts
index 9ee39e50..75de000a 100644
--- a/until/docs/types/test.ts
+++ b/until/docs/types/test.ts
@@ -64,7 +64,7 @@ function noop() {
 	until( noop, {} ); // $ExpectError
 }
 
-// The function does not compile if provided fewer than two arguments...
+// The compiler throws an error if the function is provided fewer than two arguments...
 {
 	until(); // $ExpectError
 	until( noop ); // $ExpectError
diff --git a/unzip/benchmark/benchmark.js b/unzip/benchmark/benchmark.js
index 0313d0f8..4e58fc8e 100644
--- a/unzip/benchmark/benchmark.js
+++ b/unzip/benchmark/benchmark.js
@@ -48,7 +48,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		arr[ i % len ][ 1 ] += 10.0;
 		unzipped = unzip( arr );
-		if ( !isArray( unzipped ) ) {
+		if ( typeof unzipped !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/values-in/benchmark/benchmark.js b/values-in/benchmark/benchmark.js
index 29f63d86..0d3514f0 100644
--- a/values-in/benchmark/benchmark.js
+++ b/values-in/benchmark/benchmark.js
@@ -52,7 +52,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = objectValuesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/values/benchmark/benchmark.js b/values/benchmark/benchmark.js
index 829852dc..d0157644 100644
--- a/values/benchmark/benchmark.js
+++ b/values/benchmark/benchmark.js
@@ -47,7 +47,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = objectValues( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/while/docs/types/test.ts b/while/docs/types/test.ts
index 565c8372..74cb41b1 100644
--- a/while/docs/types/test.ts
+++ b/while/docs/types/test.ts
@@ -64,7 +64,7 @@ function noop() {
 	whilst( noop, {} ); // $ExpectError
 }
 
-// The function does not compile if provided fewer than two arguments...
+// The compiler throws an error if the function is provided fewer than two arguments...
 {
 	whilst(); // $ExpectError
 	whilst( noop ); // $ExpectError
diff --git a/writable-properties-in/benchmark/benchmark.js b/writable-properties-in/benchmark/benchmark.js
index 780c8d7c..71552654 100644
--- a/writable-properties-in/benchmark/benchmark.js
+++ b/writable-properties-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = writablePropertiesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/writable-properties/benchmark/benchmark.js b/writable-properties/benchmark/benchmark.js
index 284c50fe..ad2841bb 100644
--- a/writable-properties/benchmark/benchmark.js
+++ b/writable-properties/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = writableProperties( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/writable-property-names-in/benchmark/benchmark.js b/writable-property-names-in/benchmark/benchmark.js
index 3dd4fcf1..f7effdc3 100644
--- a/writable-property-names-in/benchmark/benchmark.js
+++ b/writable-property-names-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = writablePropertyNamesIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/writable-property-names/benchmark/benchmark.js b/writable-property-names/benchmark/benchmark.js
index 226e0633..925e993b 100644
--- a/writable-property-names/benchmark/benchmark.js
+++ b/writable-property-names/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = writablePropertyNames( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/writable-property-symbols-in/benchmark/benchmark.js b/writable-property-symbols-in/benchmark/benchmark.js
index 1094d4cb..8694d03f 100644
--- a/writable-property-symbols-in/benchmark/benchmark.js
+++ b/writable-property-symbols-in/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = writablePropertySymbolsIn( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/writable-property-symbols/benchmark/benchmark.js b/writable-property-symbols/benchmark/benchmark.js
index 7b796a93..cd5934fc 100644
--- a/writable-property-symbols/benchmark/benchmark.js
+++ b/writable-property-symbols/benchmark/benchmark.js
@@ -59,7 +59,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		obj.f = randu();
 		out = writablePropertySymbols( obj );
-		if ( !isArray( out ) ) {
+		if ( typeof out !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}
diff --git a/zip/benchmark/benchmark.js b/zip/benchmark/benchmark.js
index 908a14af..219ac48a 100644
--- a/zip/benchmark/benchmark.js
+++ b/zip/benchmark/benchmark.js
@@ -48,7 +48,7 @@ bench( pkg, function benchmark( b ) {
 	for ( i = 0; i < b.iterations; i++ ) {
 		x[ i % len ] += 10.0;
 		o = zip( x, y );
-		if ( !isArray( o ) ) {
+		if ( typeof o !== 'object' ) {
 			b.fail( 'should return an array' );
 		}
 	}