Remove some easy to remove semicolons for ASI (#321)

src/transformers/chunk/asi.ts

@@ -0,0 +1,50 @@
+/**
+ * Copyright 2018 The AMP HTML Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { ChunkTransform } from '../../transform';
+import { Range } from '../../types';
+import { parse } from '../../acorn';
+import MagicString from 'magic-string';
+
+export default class ASITransform extends ChunkTransform {
+  public name = 'ASITransform';
+
+  /**
+   * Small reduction in semi-colons, removing from end of block statements.
+   * @param source source following closure compiler minification
+   */
+  public async post(source: MagicString): Promise<MagicString> {
+    const code = source.toString();
+    const program = parse(code);
+
+    if (program.body) {
+      const lastStatement = program.body[program.body.length - 1];
+      if (lastStatement) {
+        const [start, end] = lastStatement.range as Range;
+        if (lastStatement.type === 'EmptyStatement') {
+          source.remove(start, end);
+        } else {
+          const lastStatementSource = code.substring(start, end);
+          if (lastStatementSource.endsWith(';')) {
+            source.overwrite(start, end, code.substring(start, end - 1));
+          }
+        }
+      }
+    }
+
+    return source;
+  }
+}

src/transformers/chunk/const.ts

@@ -31,7 +31,7 @@ export default class ConstTransform extends ChunkTransform {
    */
   public async pre(source: MagicString): Promise<MagicString> {
     const code = source.toString();
-    const program = parse(source.toString());
+    const program = parse(code);
 
     walk.simple(program, {
       VariableDeclaration(node: VariableDeclaration) {

src/transformers/chunk/transforms.ts

@@ -30,6 +30,7 @@ import ExportTransform from './exports';
 import ImportTransform from './imports';
 import StrictTransform from './strict';
 import ConstTransform from './const';
+import ASITransform from './asi';
 import { ChunkTransform, chunkLifecycle } from '../../transform';
 import { Mangle } from '../mangle';
 import { Ebbinghaus } from '../ebbinghaus';
@@ -46,6 +47,7 @@ const TRANSFORMS: Array<typeof ChunkTransform> = [
   StrictTransform,
   ExportTransform,
   ImportTransform,
+  ASITransform,
   // Acorn cannot parse content starting here.
   HashbangApplyTransform,
 ];

test/arrow-function/fixtures/multiple-arguments.esm.advanced.js

@@ -1 +1 @@
-export var multipleArguments=(a,b)=>console.log(a,b);
+export var multipleArguments=(a,b)=>console.log(a,b)

test/arrow-function/fixtures/multiple-arguments.esm.default.js

@@ -1 +1 @@
-export var multipleArguments=(a,b)=>console.log(a,b);
+export var multipleArguments=(a,b)=>console.log(a,b)

test/arrow-function/fixtures/multiple-arguments.esm.es5.js

@@ -1 +1 @@
-export function multipleArguments(a,b){return console.log(a,b)};
+export function multipleArguments(a,b){return console.log(a,b)}

test/arrow-function/fixtures/multiple-arguments.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export var multipleArguments=(a, b) => console.log(a, b);
+export var multipleArguments=(a, b) => console.log(a, b)

test/arrow-function/fixtures/single-argument.esm.advanced.js

@@ -1 +1 @@
-export var singleArgument=a=>console.log(a);
+export var singleArgument=a=>console.log(a)

test/arrow-function/fixtures/single-argument.esm.default.js

@@ -1 +1 @@
-export var singleArgument=a=>console.log(a);
+export var singleArgument=a=>console.log(a)

test/arrow-function/fixtures/single-argument.esm.es5.js

@@ -1 +1 @@
-export function singleArgument(a){return console.log(a)};
+export function singleArgument(a){return console.log(a)}

test/arrow-function/fixtures/single-argument.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export var singleArgument=a => console.log(a);
+export var singleArgument=a => console.log(a)

test/closure-config/fixtures/prefer-config.esm.javascript.js

@@ -1 +1 @@
-console.log("foo");
+console.log("foo")

test/const-rename/fixtures/rename.esm.advanced.js

@@ -1 +1 @@
-let b=[3,4],c=[5,6];export function yes(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};
+let b=[3,4],c=[5,6];export function yes(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)}

test/const-rename/fixtures/rename.esm.default.js

@@ -1 +1 @@
-let b=[3,4],c=[5,6];export function yes(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};
+let b=[3,4],c=[5,6];export function yes(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)}

test/const-rename/fixtures/rename.esm.es5.js

@@ -1 +1 @@
-var b=[3,4],c=[5,6];export function yes(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)};
+var b=[3,4],c=[5,6];export function yes(a){return 0<=c.indexOf(a)&&0<=b.indexOf(a)}

test/const-rename/fixtures/rename.esm.pretty.js

@@ -2,4 +2,4 @@
 let b = [3, 4], c = [5, 6];
 export function yes(a) {
   return 0 <= c.indexOf(a) && 0 <= b.indexOf(a);
-};
+}

test/export-default/fixtures/array.esm.advanced.js

@@ -1 +1 @@
-export default [];
+export default []

test/export-default/fixtures/array.esm.default.js

@@ -1 +1 @@
-export default [];
+export default []

test/export-default/fixtures/array.esm.es5.js

@@ -1 +1 @@
-export default [];
+export default []

test/export-default/fixtures/array.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export default [];
+export default []

test/export-default/fixtures/arrow-function.esm.advanced.js

@@ -1 +1 @@
-export default a=>console.log(a);
+export default a=>console.log(a)

test/export-default/fixtures/arrow-function.esm.default.js

@@ -1 +1 @@
-export default a=>console.log(a);
+export default a=>console.log(a)

test/export-default/fixtures/arrow-function.esm.es5.js

@@ -1 +1 @@
-export default function(a){return console.log(a)};
+export default function(a){return console.log(a)}

test/export-default/fixtures/arrow-function.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export default a => console.log(a);
+export default a => console.log(a)

test/export-default/fixtures/class.esm.advanced.js

@@ -1 +1 @@
-class a{constructor(b){this.a=b}console(){console.log(this.a)}}export default a;
+class a{constructor(b){this.a=b}console(){console.log(this.a)}}export default a

test/export-default/fixtures/class.esm.default.js

@@ -1 +1 @@
-class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}export default a;
+class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}export default a

test/export-default/fixtures/class.esm.es5.js

@@ -1 +1 @@
-function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};export default a;
+function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};export default a

test/export-default/fixtures/class.esm.pretty.js

@@ -7,4 +7,4 @@ class a {
     console.log(this.name_);
   }
 }
-export default a;
+export default a

test/export-default/fixtures/function.esm.advanced.js

@@ -1 +1 @@
-export default function(a){console.log(a);console.log(1)};
+export default function(a){console.log(a);console.log(1)}

test/export-default/fixtures/function.esm.default.js

@@ -1 +1 @@
-export default function(a){console.log(a);console.log(1)};
+export default function(a){console.log(a);console.log(1)}

test/export-default/fixtures/function.esm.es5.js

@@ -1 +1 @@
-export default function(a){console.log(a);console.log(1)};
+export default function(a){console.log(a);console.log(1)}

test/export-default/fixtures/function.esm.pretty.js

@@ -2,4 +2,4 @@
 export default function(a) {
   console.log(a);
   console.log(1);
-};
+}

test/export-default/fixtures/identifier.esm.advanced.js

@@ -1 +1 @@
-export default 1;
+export default 1

test/export-default/fixtures/identifier.esm.default.js

@@ -1 +1 @@
-export default 1;
+export default 1

test/export-default/fixtures/identifier.esm.es5.js

@@ -1 +1 @@
-export default 1;
+export default 1

test/export-default/fixtures/identifier.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export default 1;
+export default 1

test/export-default/fixtures/named-class.esm.advanced.js

@@ -1 +1 @@
-class a{constructor(b){this.a=b}console(){console.log(this.a)}}export default a;
+class a{constructor(b){this.a=b}console(){console.log(this.a)}}export default a

test/export-default/fixtures/named-class.esm.default.js

@@ -1 +1 @@
-class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}export default a;
+class a{constructor(b){this.name_=b}console(){console.log(this.name_)}}export default a

test/export-default/fixtures/named-class.esm.es5.js

@@ -1 +1 @@
-function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};export default a;
+function a(b){this.name_=b}a.prototype.console=function(){console.log(this.name_)};export default a

test/export-default/fixtures/named-class.esm.pretty.js

@@ -7,4 +7,4 @@ class a {
     console.log(this.name_);
   }
 }
-export default a;
+export default a

test/export-default/fixtures/named-function.esm.advanced.js

@@ -1 +1 @@
-export default function(a){console.log(a);console.log(1)};
+export default function(a){console.log(a);console.log(1)}

test/export-default/fixtures/named-function.esm.default.js

@@ -1 +1 @@
-export default function(a){console.log(a);console.log(1)};
+export default function(a){console.log(a);console.log(1)}

test/export-default/fixtures/named-function.esm.es5.js

@@ -1 +1 @@
-export default function(a){console.log(a);console.log(1)};
+export default function(a){console.log(a);console.log(1)}

test/export-default/fixtures/named-function.esm.pretty.js

@@ -2,4 +2,4 @@
 export default function(a) {
   console.log(a);
   console.log(1);
-};
+}

test/export-default/fixtures/number.esm.advanced.js

@@ -1 +1 @@
-export default 42;
+export default 42

test/export-default/fixtures/number.esm.default.js

@@ -1 +1 @@
-export default 42;
+export default 42

test/export-default/fixtures/number.esm.es5.js

@@ -1 +1 @@
-export default 42;
+export default 42

test/export-default/fixtures/number.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export default 42;
+export default 42

test/export-default/fixtures/object.esm.advanced.js

@@ -1 +1 @@
-export default {key:"value"};
+export default {key:"value"}

test/export-default/fixtures/object.esm.default.js

@@ -1 +1 @@
-export default {key:"value"};
+export default {key:"value"}

test/export-default/fixtures/object.esm.es5.js

@@ -1 +1 @@
-export default {key:"value"};
+export default {key:"value"}

test/export-default/fixtures/object.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export default {key:"value"};
+export default {key:"value"}

test/export-externals/fixtures/array.esm.advanced.js

@@ -1 +1 @@
-export{exportedArray}from'./external.js';
+export{exportedArray}from'./external.js'

test/export-externals/fixtures/array.esm.default.js

@@ -1 +1 @@
-export{exportedArray}from'./external.js';
+export{exportedArray}from'./external.js'

test/export-externals/fixtures/array.esm.es5.js

@@ -1 +1 @@
-export{exportedArray}from'./external.js';
+export{exportedArray}from'./external.js'

test/export-externals/fixtures/array.esm.pretty.js

@@ -1 +1 @@
-export{exportedArray}from'./external.js';
+export{exportedArray}from'./external.js'

test/export-externals/fixtures/class.esm.advanced.js

@@ -1 +1 @@
-export{exportedClass}from'./external.js';
+export{exportedClass}from'./external.js'

test/export-externals/fixtures/class.esm.default.js

@@ -1 +1 @@
-export{exportedClass}from'./external.js';
+export{exportedClass}from'./external.js'

test/export-externals/fixtures/class.esm.es5.js

@@ -1 +1 @@
-export{exportedClass}from'./external.js';
+export{exportedClass}from'./external.js'

test/export-externals/fixtures/class.esm.pretty.js

@@ -1 +1 @@
-export{exportedClass}from'./external.js';
+export{exportedClass}from'./external.js'

test/export-externals/fixtures/const-function.esm.advanced.js

@@ -1 +1 @@
-export{constFunction}from'./external.js';
+export{constFunction}from'./external.js'

test/export-externals/fixtures/const-function.esm.default.js

@@ -1 +1 @@
-export{constFunction}from'./external.js';
+export{constFunction}from'./external.js'

test/export-externals/fixtures/const-function.esm.es5.js

@@ -1 +1 @@
-export{constFunction}from'./external.js';
+export{constFunction}from'./external.js'

test/export-externals/fixtures/const-function.esm.pretty.js

@@ -1 +1 @@
-export{constFunction}from'./external.js';
+export{constFunction}from'./external.js'

test/export-externals/fixtures/const-number.esm.advanced.js

@@ -1 +1 @@
-export{constNumber}from'./external.js';
+export{constNumber}from'./external.js'

test/export-externals/fixtures/const-number.esm.default.js

@@ -1 +1 @@
-export{constNumber}from'./external.js';
+export{constNumber}from'./external.js'

test/export-externals/fixtures/const-number.esm.es5.js

@@ -1 +1 @@
-export{constNumber}from'./external.js';
+export{constNumber}from'./external.js'

test/export-externals/fixtures/const-number.esm.pretty.js

@@ -1 +1 @@
-export{constNumber}from'./external.js';
+export{constNumber}from'./external.js'

test/export-externals/fixtures/default.esm.advanced.js

@@ -1 +1 @@
-export{default as X}from'./external.js';
+export{default as X}from'./external.js'

test/export-externals/fixtures/default.esm.default.js

@@ -1 +1 @@
-export{default as X}from'./external.js';
+export{default as X}from'./external.js'

test/export-externals/fixtures/default.esm.es5.js

@@ -1 +1 @@
-export{default as X}from'./external.js';
+export{default as X}from'./external.js'

test/export-externals/fixtures/default.esm.pretty.js

@@ -1 +1 @@
-export{default as X}from'./external.js';
+export{default as X}from'./external.js'

test/export-externals/fixtures/function.esm.advanced.js

@@ -1 +1 @@
-export{exportedFunction}from'./external.js';
+export{exportedFunction}from'./external.js'

test/export-externals/fixtures/function.esm.default.js

@@ -1 +1 @@
-export{exportedFunction}from'./external.js';
+export{exportedFunction}from'./external.js'

test/export-externals/fixtures/function.esm.es5.js

@@ -1 +1 @@
-export{exportedFunction}from'./external.js';
+export{exportedFunction}from'./external.js'

test/export-externals/fixtures/function.esm.pretty.js

@@ -1 +1 @@
-export{exportedFunction}from'./external.js';
+export{exportedFunction}from'./external.js'

test/export-externals/fixtures/local.esm.advanced.js

@@ -1 +1 @@
-export{exportedFunction as exF}from'./external.js';
+export{exportedFunction as exF}from'./external.js'

test/export-externals/fixtures/local.esm.default.js

@@ -1 +1 @@
-export{exportedFunction as exF}from'./external.js';
+export{exportedFunction as exF}from'./external.js'

test/export-externals/fixtures/local.esm.es5.js

@@ -1 +1 @@
-export{exportedFunction as exF}from'./external.js';
+export{exportedFunction as exF}from'./external.js'

test/export-externals/fixtures/local.esm.pretty.js

@@ -1 +1 @@
-export{exportedFunction as exF}from'./external.js';
+export{exportedFunction as exF}from'./external.js'

test/export-externals/fixtures/multiple-default.esm.advanced.js

@@ -1 +1 @@
-export{default as Y}from'./external-default.js';export{default as X}from'./external.js';
+export{default as Y}from'./external-default.js';export{default as X}from'./external.js'

test/export-externals/fixtures/multiple-default.esm.default.js

@@ -1 +1 @@
-export{default as Y}from'./external-default.js';export{default as X}from'./external.js';
+export{default as Y}from'./external-default.js';export{default as X}from'./external.js'

test/export-externals/fixtures/multiple-default.esm.es5.js

@@ -1 +1 @@
-export{default as Y}from'./external-default.js';export{default as X}from'./external.js';
+export{default as Y}from'./external-default.js';export{default as X}from'./external.js'

test/export-externals/fixtures/multiple-default.esm.pretty.js

@@ -1,2 +1,2 @@
-export{default as Y}from'./external-default.js';export{default as X}from'./external.js';
+export{default as Y}from'./external-default.js';export{default as X}from'./external.js'
 

test/export-externals/fixtures/object.esm.advanced.js

@@ -1 +1 @@
-export{constObject}from'./external.js';
+export{constObject}from'./external.js'

test/export-externals/fixtures/object.esm.default.js

@@ -1 +1 @@
-export{constObject}from'./external.js';
+export{constObject}from'./external.js'

test/export-externals/fixtures/object.esm.es5.js

@@ -1 +1 @@
-export{constObject}from'./external.js';
+export{constObject}from'./external.js'

test/export-externals/fixtures/object.esm.pretty.js

@@ -1 +1 @@
-export{constObject}from'./external.js';
+export{constObject}from'./external.js'

test/export-externals/fixtures/reserve-local-name.esm.advanced.js

@@ -1 +1 @@
-export{exportedFunction as a}from'y.js';a("1");
+export{exportedFunction as a}from'y.js';a("1")

test/export-externals/fixtures/reserve-local-name.esm.default.js

@@ -1 +1 @@
-export{exportedFunction as a}from'y.js';a("1");
+export{exportedFunction as a}from'y.js';a("1")

test/export-externals/fixtures/reserve-local-name.esm.es5.js

@@ -1 +1 @@
-export{exportedFunction as a}from'y.js';a("1");
+export{exportedFunction as a}from'y.js';a("1")

test/export-externals/fixtures/reserve-local-name.esm.pretty.js

@@ -1,2 +1,2 @@
 export{exportedFunction as a}from'y.js';
-a("1");
+a("1")

test/export-named/fixtures/identifier-default.esm.advanced.js

@@ -1 +1 @@
-export default 1;
+export default 1

test/export-named/fixtures/identifier-default.esm.default.js

@@ -1 +1 @@
-export default 1;
+export default 1

test/export-named/fixtures/identifier-default.esm.es5.js

@@ -1 +1 @@
-export default 1;
+export default 1

test/export-named/fixtures/identifier-default.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export default 1;
+export default 1

test/export-named/fixtures/identifier.esm.advanced.js

@@ -1 +1 @@
-export var foo=1;
+export var foo=1

test/export-named/fixtures/identifier.esm.default.js

@@ -1 +1 @@
-export var foo=1;
+export var foo=1

test/export-named/fixtures/identifier.esm.es5.js

@@ -1 +1 @@
-export var foo=1;
+export var foo=1

test/export-named/fixtures/identifier.esm.pretty.js

@@ -1,2 +1,2 @@
 
-export var foo=1;
+export var foo=1

test/export-transpilation/fixtures/named-constant.esm.advanced.js

@@ -1 +1 @@
-var b=Symbol.for("smth");export var isSmth=a=>a&&!!a[b];
+var b=Symbol.for("smth");export var isSmth=a=>a&&!!a[b]

test/export-transpilation/fixtures/named-constant.esm.default.js

@@ -1 +1 @@
-var b=Symbol.for("smth");export var isSmth=a=>a&&!!a[b];
+var b=Symbol.for("smth");export var isSmth=a=>a&&!!a[b]