util: refactor inspecting long lines

BridgeAR · BridgeAR · commit 9ced334a6c04 · 2019-06-17T21:12:19.000+02:00
Using the `util.inspect` `compact` mode set to something else than `true` resulted in breaking long lines in case the line would exceed the `breakLength` option and if it contained whitespace and or new lines. It turned out that this behavior was less useful than originally expected and it is now changed to only break on line breaks if the `breakLength` option is exceeded for the inspected string. This should be align better with the user expectation than the former behavior. PR-URL: #28055 Fixes: #27690 Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Rich Trott <rtrott@gmail.com>
diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
@@ -127,8 +127,6 @@ const numberRegExp = /^(0|[1-9][0-9]*)$/;
 const coreModuleRegExp = /^    at (?:[^/\\(]+ \(|)((?<![/\\]).+)\.js:\d+:\d+\)?$/;
 const nodeModulesRegExp = /[/\\]node_modules[/\\](.+?)(?=[/\\])/g;
 
-const readableRegExps = {};
-
 const kMinLineLength = 16;
 
 // Constants to map the iterator state.
@@ -1055,37 +1053,12 @@ function formatBigInt(fn, value) {
 function formatPrimitive(fn, value, ctx) {
   if (typeof value === 'string') {
     if (ctx.compact !== true &&
-        ctx.indentationLvl + value.length + 4 > ctx.breakLength &&
-        value.length > kMinLineLength) {
-      // Subtract the potential quotes, the space and the plus as well (4).
-      const rawMaxLineLength = ctx.breakLength - ctx.indentationLvl - 4;
-      const maxLineLength = Math.max(rawMaxLineLength, kMinLineLength);
-      const lines = Math.ceil(value.length / maxLineLength);
-      const averageLineLength = Math.ceil(value.length / lines);
-      const divisor = Math.max(averageLineLength, kMinLineLength);
-      if (readableRegExps[divisor] === undefined) {
-        // Build a new RegExp that naturally breaks text into multiple lines.
-        //
-        // Rules
-        // 1. Greedy match all text up the max line length that ends with a
-        //    whitespace or the end of the string.
-        // 2. If none matches, non-greedy match any text up to a whitespace or
-        //    the end of the string.
-        //
-        // eslint-disable-next-line max-len, node-core/no-unescaped-regexp-dot
-        readableRegExps[divisor] = new RegExp(`(.|\\n){1,${divisor}}(\\s|$)|(\\n|.)+?(\\s|$)`, 'gm');
-      }
-      const matches = value.match(readableRegExps[divisor]);
-      if (matches.length > 1) {
-        const indent = ' '.repeat(ctx.indentationLvl);
-        let res = `${fn(strEscape(matches[0]), 'string')} +\n`;
-        const lastIndex = matches.length - 1;
-        for (let i = 1; i < lastIndex; i++) {
-          res += `${indent}  ${fn(strEscape(matches[i]), 'string')} +\n`;
-        }
-        res += `${indent}  ${fn(strEscape(matches[lastIndex]), 'string')}`;
-        return res;
-      }
+        value.length > kMinLineLength &&
+        value.length > ctx.breakLength - ctx.indentationLvl - 4) {
+      return value
+        .split(/(?<=\n)/)
+        .map((line) => fn(strEscape(line), 'string'))
+        .join(` +\n${' '.repeat(ctx.indentationLvl + 2)}`);
     }
     return fn(strEscape(value), 'string');
   }
diff --git a/test/parallel/test-util-inspect.js b/test/parallel/test-util-inspect.js
@@ -93,7 +93,7 @@ assert.strictEqual(util.inspect(new Date('')), (new Date('')).toString());
 assert.strictEqual(util.inspect('\n\u0001'), "'\\n\\u0001'");
 assert.strictEqual(
   util.inspect(`${Array(75).fill(1)}'\n\u001d\n\u0003`),
-  `"${Array(75).fill(1)}'\\n" +\n  '\\u001d\\n\\u0003'`
+  `"${Array(75).fill(1)}'\\n" +\n  '\\u001d\\n' +\n  '\\u0003'`
 );
 assert.strictEqual(util.inspect([]), '[]');
 assert.strictEqual(util.inspect(Object.create([])), 'Array {}');
@@ -1487,10 +1487,9 @@ util.inspect(process);
     '    2,',
     '    [',
     '      [',
-    "        'Lorem ipsum dolor\\nsit amet,\\tconsectetur ' +",
-    "          'adipiscing elit, sed do eiusmod tempor ' +",
-    "          'incididunt ut labore et dolore magna ' +",
-    "          'aliqua.',",
+    "        'Lorem ipsum dolor\\n' +",
+    "          'sit amet,\\tconsectetur adipiscing elit, sed do eiusmod " +
+      "tempor incididunt ut labore et dolore magna aliqua.',",
     "        'test',",
     "        'foo'",
     '      ]',
@@ -1507,12 +1506,9 @@ util.inspect(process);
 
   out = util.inspect(o.a[2][0][0], { compact: false, breakLength: 30 });
   expect = [
-    "'Lorem ipsum dolor\\nsit ' +",
-    "  'amet,\\tconsectetur ' +",
-    "  'adipiscing elit, sed do ' +",
-    "  'eiusmod tempor incididunt ' +",
-    "  'ut labore et dolore magna ' +",
-    "  'aliqua.'"
+    "'Lorem ipsum dolor\\n' +",
+    "  'sit amet,\\tconsectetur adipiscing elit, sed do eiusmod tempor " +
+      "incididunt ut labore et dolore magna aliqua.'"
   ].join('\n');
   assert.strictEqual(out, expect);
 
@@ -1526,30 +1522,7 @@ util.inspect(process);
     '12 45 78 01 34 67 90 23 56 89 123456789012345678901234567890',
     { compact: false, breakLength: 3 });
   expect = [
-    "'12 45 78 01 34 ' +",
-    "  '67 90 23 56 89 ' +",
-    "  '123456789012345678901234567890'"
-  ].join('\n');
-  assert.strictEqual(out, expect);
-
-  out = util.inspect(
-    '12 45 78 01 34 67 90 23 56 89 1234567890123 0',
-    { compact: false, breakLength: 3 });
-  expect = [
-    "'12 45 78 01 34 ' +",
-    "  '67 90 23 56 89 ' +",
-    "  '1234567890123 0'"
-  ].join('\n');
-  assert.strictEqual(out, expect);
-
-  out = util.inspect(
-    '12 45 78 01 34 67 90 23 56 89 12345678901234567 0',
-    { compact: false, breakLength: 3 });
-  expect = [
-    "'12 45 78 01 34 ' +",
-    "  '67 90 23 56 89 ' +",
-    "  '12345678901234567 ' +",
-    "  '0'"
+    "'12 45 78 01 34 67 90 23 56 89 123456789012345678901234567890'"
   ].join('\n');
   assert.strictEqual(out, expect);
 
@@ -1588,7 +1561,7 @@ util.inspect(process);
 
   o[util.inspect.custom] = () => ({ a: '12 45 78 01 34 67 90 23' });
   out = util.inspect(o, { compact: false, breakLength: 3 });
-  expect = "{\n  a: '12 45 78 01 34 ' +\n    '67 90 23'\n}";
+  expect = "{\n  a: '12 45 78 01 34 67 90 23'\n}";
   assert.strictEqual(out, expect);
 }
 
@@ -2192,16 +2165,13 @@ assert.strictEqual(
     '    b: {',
     '      x: 5,',
     '      c: {',
-    "        x: '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ' +",
-    "          '10000000000000000 00000000000000000 ',",
+    "        x: '10000000000000000 00000000000000000 10000000000000000 " +
+      '00000000000000000 10000000000000000 00000000000000000 ' +
+      '10000000000000000 00000000000000000 10000000000000000 ' +
+      '00000000000000000 10000000000000000 00000000000000000 ' +
+      '10000000000000000 00000000000000000 10000000000000000 ' +
+      '00000000000000000 10000000000000000 00000000000000000 ' +
+      "10000000000000000 00000000000000000 ',",
     '        d: 2,',
     '        e: 3',
     '      }',
