repl: make autocomplete case-insensitive

This changes autocomplete suggestion filter to ignore input case
allowing for more autosuggest results shown on the screen

Fixes: https://github.com/nodejs/node/issues/41631

PR-URL: https://github.com/nodejs/node/pull/41632
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

4 files changed, 138 insertions, 64 deletions

diff --git a/lib/repl.js b/lib/repl.js
index 7c17272f6e6..eeb8594eff4 100644
--- a/lib/repl.js
+++ b/lib/repl.js
@@ -94,6 +94,7 @@ const {
   StringPrototypeStartsWith,
   StringPrototypeTrim,
   StringPrototypeTrimLeft,
+  StringPrototypeToLocaleLowerCase,
   Symbol,
   SyntaxError,
   SyntaxErrorPrototype,
@@ -1301,8 +1302,8 @@ function complete(line, callback) {
   // Ignore right whitespace. It could change the outcome.
   line = StringPrototypeTrimLeft(line);
 
-  // REPL commands (e.g. ".break").
   let filter = '';
+  // REPL commands (e.g. ".break").
   if (RegExpPrototypeTest(/^\s*\.(\w*)$/, line)) {
     ArrayPrototypePush(completionGroups, ObjectKeys(this.commands));
     completeOn = StringPrototypeMatch(line, /^\s*\.(\w*)$/)[1];
@@ -1545,11 +1546,16 @@ function complete(line, callback) {
     // Filter, sort (within each group), uniq and merge the completion groups.
     if (completionGroups.length && filter) {
       const newCompletionGroups = [];
+      const lowerCaseFilter = StringPrototypeToLocaleLowerCase(filter);
       ArrayPrototypeForEach(completionGroups, (group) => {
-        const filteredGroup = ArrayPrototypeFilter(
-          group,
-          (str) => StringPrototypeStartsWith(str, filter)
-        );
+        const filteredGroup = ArrayPrototypeFilter(group, (str) => {
+          // Filter is always case-insensitive following chromium autocomplete
+          // behavior.
+          return StringPrototypeStartsWith(
+            StringPrototypeToLocaleLowerCase(str),
+            lowerCaseFilter
+          );
+        });
         if (filteredGroup.length) {
           ArrayPrototypePush(newCompletionGroups, filteredGroup);
         }
diff --git a/test/parallel/test-repl-history-navigation.js b/test/parallel/test-repl-history-navigation.js
index 29cb7816f0f..39ccc3732c3 100644
--- a/test/parallel/test-repl-history-navigation.js
+++ b/test/parallel/test-repl-history-navigation.js
@@ -74,6 +74,7 @@ const tests = [
     env: { NODE_REPL_HISTORY: defaultHistoryPath },
     test: [ 'let ab = 45', ENTER,
             '555 + 909', ENTER,
+            'let autocompleteMe = 123', ENTER,
             '{key : {key2 :[] }}', ENTER,
             'Array(100).fill(1).map((e, i) => i ** i)', LEFT, LEFT, DELETE,
             '2', ENTER],
@@ -82,7 +83,7 @@ const tests = [
   },
   {
     env: { NODE_REPL_HISTORY: defaultHistoryPath },
-    test: [UP, UP, UP, UP, UP, DOWN, DOWN, DOWN, DOWN, DOWN],
+    test: [UP, UP, UP, UP, UP, UP, DOWN, DOWN, DOWN, DOWN, DOWN, DOWN],
     expected: [prompt,
                `${prompt}Array(100).fill(1).map((e, i) => i ** 2)`,
                prev && '\n// [ 0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, ' +
@@ -92,6 +93,7 @@ const tests = [
                  ' 2025, 2116, 2209,...',
                `${prompt}{key : {key2 :[] }}`,
                prev && '\n// { key: { key2: [] } }',
+               `${prompt}let autocompleteMe = 123`,
                `${prompt}555 + 909`,
                prev && '\n// 1464',
                `${prompt}let ab = 45`,
@@ -99,6 +101,7 @@ const tests = [
                `${prompt}let ab = 45`,
                `${prompt}555 + 909`,
                prev && '\n// 1464',
+               `${prompt}let autocompleteMe = 123`,
                `${prompt}{key : {key2 :[] }}`,
                prev && '\n// { key: { key2: [] } }',
                `${prompt}Array(100).fill(1).map((e, i) => i ** 2)`,
@@ -128,7 +131,7 @@ const tests = [
     preview: false,
     showEscapeCodes: true,
     test: [
-      '55', UP, UP, UP, UP, UP, UP, ENTER,
+      '55', UP, UP, UP, UP, UP, UP, UP, ENTER,
     ],
     expected: [
       '\x1B[1G', '\x1B[0J', prompt, '\x1B[3G',
@@ -185,10 +188,10 @@ const tests = [
       ENTER,
       'veryLongName'.repeat(30),
       ENTER,
-      `${'\x1B[90m \x1B[39m'.repeat(235)} fun`,
+      `${'\x1B[90m \x1B[39m'.repeat(229)} aut`,
       ESCAPE,
       ENTER,
-      `${' '.repeat(236)} fun`,
+      `${' '.repeat(230)} aut`,
       ESCAPE,
       ENTER,
     ],
@@ -236,19 +239,20 @@ const tests = [
       prompt, '\x1B[3G',
       // 1. UP
       // This exceeds the maximum columns (250):
-      // Whitespace + prompt + ' // '.length + 'function'.length
-      // 236 + 2 + 4 + 8
+      // Whitespace + prompt + ' // '.length + 'autocompleteMe'.length
+      // 230 + 2 + 4 + 14
       '\x1B[1G', '\x1B[0J',
-      `${prompt}${' '.repeat(236)} fun`, '\x1B[243G',
-      ' // ction', '\x1B[243G',
-      ' // ction', '\x1B[243G',
+      `${prompt}${' '.repeat(230)} aut`, '\x1B[237G',
+      ' // ocompleteMe', '\x1B[237G',
+      '\n// 123', '\x1B[237G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       '\x1B[0K',
       // 2. UP
       '\x1B[1G', '\x1B[0J',
-      `${prompt}${' '.repeat(235)} fun`, '\x1B[242G',
-      // TODO(BridgeAR): Investigate why the preview is generated twice.
-      ' // ction', '\x1B[242G',
-      ' // ction', '\x1B[242G',
+      `${prompt}${' '.repeat(229)} aut`, '\x1B[236G',
+      ' // ocompleteMe', '\x1B[236G',
+      '\n// 123', '\x1B[236G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // Preview cleanup
       '\x1B[0K',
       // 3. UP
@@ -326,8 +330,8 @@ const tests = [
     skip: !process.features.inspector,
     checkTotal: true,
     test: [
-      'fu',
-      'n',
+      'au',
+      't',
       RIGHT,
       BACKSPACE,
       LEFT,
@@ -353,74 +357,93 @@ const tests = [
     // K = Erase in line; 0 = right; 1 = left; 2 = total
     expected: [
       // 0.
-      // 'f'
-      '\x1B[1G', '\x1B[0J', prompt, '\x1B[3G', 'f',
+      // 'a'
+      '\x1B[1G', '\x1B[0J', prompt, '\x1B[3G', 'a',
       // 'u'
-      'u', ' // nction', '\x1B[5G',
-      // 'n' - Cleanup
+      'u', ' // tocompleteMe', '\x1B[5G',
+      '\n// 123', '\x1B[5G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
+      // 't' - Cleanup
       '\x1B[0K',
-      'n', ' // ction', '\x1B[6G',
+      't', ' // ocompleteMe', '\x1B[6G',
+      '\n// 123', '\x1B[6G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // 1. Right. Cleanup
       '\x1B[0K',
-      'ction',
+      'ocompleteMe',
+      '\n// 123', '\x1B[17G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // 2. Backspace. Refresh
-      '\x1B[1G', '\x1B[0J', `${prompt}functio`, '\x1B[10G',
+      '\x1B[1G', '\x1B[0J', `${prompt}autocompleteM`, '\x1B[16G',
       // Autocomplete and refresh?
-      ' // n', '\x1B[10G', ' // n', '\x1B[10G',
+      ' // e', '\x1B[16G',
+      '\n// 123', '\x1B[16G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // 3. Left. Cleanup
       '\x1B[0K',
-      '\x1B[1D', '\x1B[10G', ' // n', '\x1B[9G',
+      '\x1B[1D', '\x1B[16G', ' // e', '\x1B[15G',
       // 4. Left. Cleanup
-      '\x1B[10G', '\x1B[0K', '\x1B[9G',
-      '\x1B[1D', '\x1B[10G', ' // n', '\x1B[8G',
+      '\x1B[16G', '\x1B[0K', '\x1B[15G',
+      '\x1B[1D', '\x1B[16G', ' // e', '\x1B[14G',
       // 5. 'A' - Cleanup
-      '\x1B[10G', '\x1B[0K', '\x1B[8G',
+      '\x1B[16G', '\x1B[0K', '\x1B[14G',
       // Refresh
-      '\x1B[1G', '\x1B[0J', `${prompt}functAio`, '\x1B[9G',
+      '\x1B[1G', '\x1B[0J', `${prompt}autocompletAeM`, '\x1B[15G',
       // 6. Backspace. Refresh
-      '\x1B[1G', '\x1B[0J', `${prompt}functio`, '\x1B[8G', '\x1B[10G', ' // n',
-      '\x1B[8G', '\x1B[10G', ' // n',
-      '\x1B[8G', '\x1B[10G',
+      '\x1B[1G', '\x1B[0J', `${prompt}autocompleteM`,
+      '\x1B[14G', '\x1B[16G', ' // e',
+      '\x1B[14G', '\x1B[16G', ' // e',
+      '\x1B[14G', '\x1B[16G',
       // 7. Go to end. Cleanup
-      '\x1B[0K', '\x1B[8G', '\x1B[2C',
-      'n',
+      '\x1B[0K', '\x1B[14G', '\x1B[2C',
+      'e',
+      '\n// 123', '\x1B[17G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // 8. Backspace. Refresh
-      '\x1B[1G', '\x1B[0J', `${prompt}functio`, '\x1B[10G',
+      '\x1B[1G', '\x1B[0J', `${prompt}autocompleteM`, '\x1B[16G',
       // Autocomplete
-      ' // n', '\x1B[10G', ' // n', '\x1B[10G',
+      ' // e', '\x1B[16G',
+      '\n// 123', '\x1B[16G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // 9. Word left. Cleanup
-      '\x1B[0K', '\x1B[7D', '\x1B[10G', ' // n', '\x1B[3G', '\x1B[10G',
+      '\x1B[0K', '\x1B[13D', '\x1B[16G', ' // e', '\x1B[3G', '\x1B[16G',
       // 10. Word right. Cleanup
-      '\x1B[0K', '\x1B[3G', '\x1B[7C', ' // n', '\x1B[10G',
+      '\x1B[0K', '\x1B[3G', '\x1B[13C', ' // e', '\x1B[16G',
+      '\n// 123', '\x1B[16G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // 11. ESCAPE
       '\x1B[0K',
       // 12. ENTER
       '\r\n',
-      'Uncaught ReferenceError: functio is not defined\n',
+      'Uncaught ReferenceError: autocompleteM is not defined\n',
       '\x1B[1G', '\x1B[0J',
       // 13. UP
       prompt, '\x1B[3G', '\x1B[1G', '\x1B[0J',
-      `${prompt}functio`, '\x1B[10G',
-      ' // n', '\x1B[10G',
-      ' // n', '\x1B[10G',
+      `${prompt}autocompleteM`, '\x1B[16G',
+      ' // e', '\x1B[16G',
+      '\n// 123', '\x1B[16G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
       // 14. LEFT
-      '\x1B[0K', '\x1B[1D',
-      '\x1B[10G', ' // n', '\x1B[9G', '\x1B[10G',
+      '\x1B[0K', '\x1B[1D', '\x1B[16G',
+      ' // e', '\x1B[15G', '\x1B[16G',
       // 15. ENTER
-      '\x1B[0K', '\x1B[9G', '\x1B[1C',
+      '\x1B[0K', '\x1B[15G', '\x1B[1C',
       '\r\n',
-      'Uncaught ReferenceError: functio is not defined\n',
+      'Uncaught ReferenceError: autocompleteM is not defined\n',
       '\x1B[1G', '\x1B[0J',
-      '> ', '\x1B[3G',
+      prompt, '\x1B[3G',
       // 16. UP
       '\x1B[1G', '\x1B[0J',
-      '> functio', '\x1B[10G',
-      ' // n', '\x1B[10G',
-      ' // n', '\x1B[10G', '\x1B[0K',
+      `${prompt}autocompleteM`, '\x1B[16G',
+      ' // e', '\x1B[16G',
+      '\n// 123', '\x1B[16G',
+      '\x1B[1A', '\x1B[1B', '\x1B[2K', '\x1B[1A',
+      '\x1B[0K',
       // 17. ENTER
-      'n', '\r\n',
+      'e', '\r\n',
+      '123\n',
       '\x1B[1G', '\x1B[0J',
-      '... ', '\x1B[5G',
+      prompt, '\x1B[3G',
       '\r\n',
     ],
     clean: true
diff --git a/test/parallel/test-repl-reverse-search.js b/test/parallel/test-repl-reverse-search.js
index 5165dc2820d..2808c953431 100644
--- a/test/parallel/test-repl-reverse-search.js
+++ b/test/parallel/test-repl-reverse-search.js
@@ -212,9 +212,7 @@ const tests = [
     expected: [
       '\x1B[1G', '\x1B[0J',
       prompt, '\x1B[3G',
-      'f', 'u', ' // nction',
-      '\x1B[5G', '\x1B[0K',
-      '\nbck-i-search: _', '\x1B[1A', '\x1B[5G',
+      'f', 'u', '\nbck-i-search: _', '\x1B[1A', '\x1B[5G',
       '\x1B[3G', '\x1B[0J',
       '{key : {key2 :[] }}\nbck-i-search: }_', '\x1B[1A', '\x1B[21G',
       '\x1B[3G', '\x1B[0J',
diff --git a/test/parallel/test-repl-tab-complete.js b/test/parallel/test-repl-tab-complete.js
index 5b60c88dc71..cc211d6da8a 100644
--- a/test/parallel/test-repl-tab-complete.js
+++ b/test/parallel/test-repl-tab-complete.js
@@ -205,6 +205,38 @@ testMe.complete('str.len', common.mustCall(function(error, data) {
 
 putIn.run(['.clear']);
 
+// Tab completion should be case-insensitive if member part is lower-case
+putIn.run([
+  'var foo = { barBar: 1, BARbuz: 2, barBLA: 3 };',
+]);
+testMe.complete(
+  'foo.b',
+  common.mustCall(function(error, data) {
+    assert.deepStrictEqual(data, [
+      ['foo.BARbuz', 'foo.barBLA', 'foo.barBar'],
+      'foo.b',
+    ]);
+  })
+);
+
+putIn.run(['.clear']);
+
+// Tab completion should be case-insensitive if member part is upper-case
+putIn.run([
+  'var foo = { barBar: 1, BARbuz: 2, barBLA: 3 };',
+]);
+testMe.complete(
+  'foo.B',
+  common.mustCall(function(error, data) {
+    assert.deepStrictEqual(data, [
+      ['foo.BARbuz', 'foo.barBLA', 'foo.barBar'],
+      'foo.B',
+    ]);
+  })
+);
+
+putIn.run(['.clear']);
+
 // Tab completion should not break on spaces
 const spaceTimeout = setTimeout(function() {
   throw new Error('timeout');
@@ -588,12 +620,27 @@ const testNonGlobal = repl.start({
   useGlobal: false
 });
 
-const builtins = [['Infinity', 'Int16Array', 'Int32Array',
-                   'Int8Array'], 'I'];
+const builtins = [
+  [
+    'if',
+    'import',
+    'in',
+    'instanceof',
+    '',
+    'Infinity',
+    'Int16Array',
+    'Int32Array',
+    'Int8Array',
+    ...(common.hasIntl ? ['Intl'] : []),
+    'inspector',
+    'isFinite',
+    'isNaN',
+    '',
+    'isPrototypeOf',
+  ],
+  'I',
+];
 
-if (common.hasIntl) {
-  builtins[0].push('Intl');
-}
 testNonGlobal.complete('I', common.mustCall((error, data) => {
   assert.deepStrictEqual(data, builtins);
 }));