console: Support for console constructor groupIndentation options

doc/api/console.md

@@ -81,16 +81,19 @@ const { Console } = console;
 ### `new Console(options)`
 <!-- YAML
 changes:
-  - version: v8.0.0
-    pr-url: https://github.com/nodejs/node/pull/9744
-    description: The `ignoreErrors` option was introduced.
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/32964
+    description: The `groupIndentation` option was introduced.
+  - version: v11.7.0
+    pr-url: https://github.com/nodejs/node/pull/24978
+    description: The `inspectOptions` option is introduced.
   - version: v10.0.0
     pr-url: https://github.com/nodejs/node/pull/19372
     description: The `Console` constructor now supports an `options` argument,
                  and the `colorMode` option was introduced.
-  - version: v11.7.0
-    pr-url: https://github.com/nodejs/node/pull/24978
-    description: The `inspectOptions` option is introduced.
+  - version: v8.0.0
+    pr-url: https://github.com/nodejs/node/pull/9744
+    description: The `ignoreErrors` option was introduced.
 -->
 
 * `options` {Object}
@@ -107,6 +110,8 @@ changes:
     **Default:** `'auto'`.
   * `inspectOptions` {Object} Specifies options that are passed along to
     [`util.inspect()`][].
+  * `groupIndentation` {number} Set group indentation.
+    **Default:** `2`.
 
 Creates a new `Console` with one or two writable stream instances. `stdout` is a
 writable stream to print log or info output. `stderr` is used for warning or
@@ -302,11 +307,16 @@ values are concatenated. See [`util.format()`][] for more information.
 ### `console.group([...label])`
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/32964
+    description: The `groupIndentation` option was introduced.
 -->
 
 * `...label` {any}
 
-Increases indentation of subsequent lines by two spaces.
+Increases indentation of subsequent lines by spaces for `groupIndentation`
+length.
 
 If one or more `label`s are provided, those are printed first without the
 additional indentation.
@@ -321,9 +331,14 @@ An alias for [`console.group()`][].
 ### `console.groupEnd()`
 <!-- YAML
 added: v8.5.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/32964
+    description: The `groupIndentation` option was introduced.
 -->
 
-Decreases indentation of subsequent lines by two spaces.
+Decreases indentation of subsequent lines by spaces for `groupIndentation`
+length.
 
 ### `console.info([data][, ...args])`
 <!-- YAML

lib/internal/console/constructor.js

@@ -32,6 +32,7 @@ const {
     ERR_INCOMPATIBLE_OPTION_PAIR,
   },
 } = require('internal/errors');
+const { validateInteger } = require('internal/validators');
 const { previewEntries } = internalBinding('util');
 const { Buffer: { isBuffer } } = require('buffer');
 const {
@@ -52,12 +53,14 @@ const kTraceInstant = 'n'.charCodeAt(0);
 const kSecond = 1000;
 const kMinute = 60 * kSecond;
 const kHour = 60 * kMinute;
+const kMaxGroupIndentation = 1000;
 
 // Lazy loaded for startup performance.
 let cliTable;
 
 // Track amount of indentation required via `console.group()`.
 const kGroupIndent = Symbol('kGroupIndent');
+const kGroupIndentationWidth = Symbol('kGroupIndentWidth');
 const kFormatForStderr = Symbol('kFormatForStderr');
 const kFormatForStdout = Symbol('kFormatForStdout');
 const kGetInspectOptions = Symbol('kGetInspectOptions');
@@ -93,7 +96,8 @@ function Console(options /* or: stdout, stderr, ignoreErrors = true */) {
     stderr = stdout,
     ignoreErrors = true,
     colorMode = 'auto',
-    inspectOptions
+    inspectOptions,
+    groupIndentation,
   } = options;
 
   if (!stdout || typeof stdout.write !== 'function') {
@@ -106,6 +110,11 @@ function Console(options /* or: stdout, stderr, ignoreErrors = true */) {
   if (typeof colorMode !== 'boolean' && colorMode !== 'auto')
     throw new ERR_INVALID_ARG_VALUE('colorMode', colorMode);
 
+  if (groupIndentation !== undefined) {
+    validateInteger(groupIndentation, 'groupIndentation',
+                    0, kMaxGroupIndentation);
+  }
+
   if (typeof inspectOptions === 'object' && inspectOptions !== null) {
     if (inspectOptions.colors !== undefined &&
         options.colorMode !== undefined) {
@@ -130,7 +139,7 @@ function Console(options /* or: stdout, stderr, ignoreErrors = true */) {
   }
 
   this[kBindStreamsEager](stdout, stderr);
-  this[kBindProperties](ignoreErrors, colorMode);
+  this[kBindProperties](ignoreErrors, colorMode, groupIndentation);
 }
 
 const consolePropAttributes = {
@@ -181,7 +190,8 @@ Console.prototype[kBindStreamsLazy] = function(object) {
   });
 };
 
-Console.prototype[kBindProperties] = function(ignoreErrors, colorMode) {
+Console.prototype[kBindProperties] = function(ignoreErrors, colorMode,
+                                              groupIndentation = 2) {
   ObjectDefineProperties(this, {
     '_stdoutErrorHandler': {
       ...consolePropAttributes,
@@ -200,7 +210,11 @@ Console.prototype[kBindProperties] = function(ignoreErrors, colorMode) {
     [kCounts]: { ...consolePropAttributes, value: new Map() },
     [kColorMode]: { ...consolePropAttributes, value: colorMode },
     [kIsConsole]: { ...consolePropAttributes, value: true },
-    [kGroupIndent]: { ...consolePropAttributes, value: '' }
+    [kGroupIndent]: { ...consolePropAttributes, value: '' },
+    [kGroupIndentationWidth]: {
+      ...consolePropAttributes,
+      value: groupIndentation
+    },
   });
 };
 
@@ -403,12 +417,13 @@ const consoleMethods = {
     if (data.length > 0) {
       this.log(...data);
     }
-    this[kGroupIndent] += '  ';
+    this[kGroupIndent] += ' '.repeat(this[kGroupIndentationWidth]);
   },
 
   groupEnd() {
     this[kGroupIndent] =
-      this[kGroupIndent].slice(0, this[kGroupIndent].length - 2);
+      this[kGroupIndent].slice(0, this[kGroupIndent].length -
+        this[kGroupIndentationWidth]);
   },
 
   // https://console.spec.whatwg.org/#table

test/parallel/test-console-group.js

@@ -12,7 +12,7 @@ const Console = require('console').Console;
 
 let c, stdout, stderr;
 
-function setup() {
+function setup(groupIndentation) {
   stdout = '';
   hijackStdout(function(data) {
     stdout += data;
@@ -25,7 +25,8 @@ function setup() {
 
   c = new Console({ stdout: process.stdout,
                     stderr: process.stderr,
-                    colorMode: false });
+                    colorMode: false,
+                    groupIndentation: groupIndentation });
 }
 
 function teardown() {
@@ -155,3 +156,86 @@ function teardown() {
   assert(!keys.includes('Symbol(groupIndent)'),
          'groupIndent should not be enumerable');
 }
+
+// Check custom groupIndentation.
+{
+  setup(3);
+  const expectedOut = 'Set the groupIndentation parameter to 3\n' +
+                      'This is the outer level\n' +
+                      '   Level 2\n' +
+                      '      Level 3\n' +
+                      '   Back to level 2\n' +
+                      'Back to the outer level\n' +
+                      'Still at the outer level\n';
+
+
+  const expectedErr = '      More of level 3\n';
+
+  c.log('Set the groupIndentation parameter to 3');
+  c.log('This is the outer level');
+  c.group();
+  c.log('Level 2');
+  c.group();
+  c.log('Level 3');
+  c.warn('More of level 3');
+  c.groupEnd();
+  c.log('Back to level 2');
+  c.groupEnd();
+  c.log('Back to the outer level');
+  c.groupEnd();
+  c.log('Still at the outer level');
+
+  assert.strictEqual(stdout, expectedOut);
+  assert.strictEqual(stderr, expectedErr);
+  teardown();
+}
+
+// Check the correctness of the groupIndentation parameter.
+{
+  // TypeError
+  [null, 'str', [], false, true, {}].forEach((e) => {
+    assert.throws(
+      () => {
+        new Console({ stdout: process.stdout,
+                      stderr: process.stderr,
+                      groupIndentation: e });
+      },
+      {
+        code: 'ERR_INVALID_ARG_TYPE',
+        name: 'TypeError'
+      }
+    );
+  });
+
+  // RangeError for integer
+  [NaN, 1.01].forEach((e) => {
+    assert.throws(
+      () => {
+        new Console({ stdout: process.stdout,
+                      stderr: process.stderr,
+                      groupIndentation: e });
+      },
+      {
+        code: 'ERR_OUT_OF_RANGE',
+        name: 'RangeError',
+        message: /an integer/,
+      }
+    );
+  });
+
+  // RangeError
+  [-1, 1001].forEach((e) => {
+    assert.throws(
+      () => {
+        new Console({ stdout: process.stdout,
+                      stderr: process.stderr,
+                      groupIndentation: e });
+      },
+      {
+        code: 'ERR_OUT_OF_RANGE',
+        name: 'RangeError',
+        message: />= 0 && <= 1000/,
+      }
+    );
+  });
+}