From 992ea4af5a7dcefb6f4fb95b2decaa90f14fe8a9 Mon Sep 17 00:00:00 2001
From: Ruslan Lopatin <ruslan.lopatin@gmail.com>
Date: Mon, 2 Aug 2021 15:55:44 +0700
Subject: [PATCH] `logline`: Report plain separated values as is

---
 src/loggable/logline.spec.ts | 12 +++++
 src/loggable/logline.ts      | 85 +++++++++++++++++++-----------------
 2 files changed, 57 insertions(+), 40 deletions(-)

diff --git a/src/loggable/logline.spec.ts b/src/loggable/logline.spec.ts
index 514d8a0..45ef66b 100644
--- a/src/loggable/logline.spec.ts
+++ b/src/loggable/logline.spec.ts
@@ -10,6 +10,18 @@ describe('logline', () => {
     toLog: () => [],
   };
 
+  it('reports single value as is', () => {
+    expect(log(logline`${1}`)).toEqual([1]);
+  });
+  it('reports leading value as is', () => {
+    expect(log(logline`${1} suffix`)).toEqual([1, 'suffix']);
+  });
+  it('reports trailing value as is', () => {
+    expect(log(logline`prefix ${1}`)).toEqual(['prefix', 1]);
+  });
+  it('reports separated values as is', () => {
+    expect(log(logline`${1} ${2} ${3} ${4}`)).toEqual([1, 2, 3, 4]);
+  });
   it('joins non-separate values', () => {
     expect(log(logline`1${2}3${4}5`)).toEqual(['12345']);
   });
diff --git a/src/loggable/logline.ts b/src/loggable/logline.ts
index 981d12e..0afd968 100644
--- a/src/loggable/logline.ts
+++ b/src/loggable/logline.ts
@@ -12,51 +12,56 @@ const logline$append = (result: unknown[], str: string): void => {
   }
 };
 const logline$join = (result: unknown[], joins: unknown[]): void => {
-  if (joins.length) {
-
-    const loggable: Loggable = {
-      toLog(target: DueLog): string | void {
-
-        // Remember the containing log line and position.
-        const { on = 'out', line, index } = target;
-
-        // The loggable to apply after joining.
-        const endJoin: Loggable = {
-          toLog(target) {
-            // Read the join results.
-            joins = target.line.slice(0, -1); // The last element is this loggable.
+  if (!joins.length) {
+    return;
+  }
+  if (joins.length === 1) {
+    result.push(joins[0]);
+    return;
+  }
 
-            if (!joins.length) {
-              // Nothing left to join.
-              line.splice(index, 1);
-              // Restore containing log line with `logline` removed.
-              target.line = line;
-              // Go on from the same position.
-              target.index = index;
+  const loggable: Loggable = {
+    toLog(target: DueLog): string | void {
 
-              return;
-            }
+      // Remember the containing log line and position.
+      const { on = 'out', line, index } = target;
 
-            if (on === 'out') {
-              // Finally join into a string.
-              line[index] = joins.join('');
-            }
+      // The loggable to apply after joining.
+      const endJoin: Loggable = {
+        toLog(target) {
+          // Read the join results.
+          joins = target.line.slice(0, -1); // The last element is this loggable.
 
-            // Restore containing log line.
+          if (!joins.length) {
+            // Nothing left to join.
+            line.splice(index, 1);
+            // Restore containing log line with `logline` removed.
             target.line = line;
-            // Go on from the next element to avoid immediate re-processing.
-            target.index = index + 1;
-          },
-        };
-
-        // Initiate joining by replacing a log line to process.
-        target.line = [...joins, /* resumes normal processing */ endJoin];
-        target.index = 0;
-      },
-    };
-
-    result.push(loggable);
-  }
+            // Go on from the same position.
+            target.index = index;
+
+            return;
+          }
+
+          if (on === 'out') {
+            // Finally join into a string.
+            line[index] = joins.join('');
+          }
+
+          // Restore containing log line.
+          target.line = line;
+          // Go on from the next element to avoid immediate re-processing.
+          target.index = index + 1;
+        },
+      };
+
+      // Initiate joining by replacing a log line to process.
+      target.line = [...joins, /* resumes normal processing */ endJoin];
+      target.index = 0;
+    },
+  };
+
+  result.push(loggable);
 };
 
 /**