repl: add support for custom completions

Allow user code to override the default `complete()` function from `readline.Interface`. See: https://nodejs.org/api/readline.html#readline_use_of_the_completer_function Ref: nodejs/node-v0.x-archive#8484 PR-URL: #7527 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Lance Ball <lball@redhat.com>

Author: diosney

doc/api/repl.md

@@ -382,6 +382,8 @@ added: v0.1.91
  `undefined`. Defaults to `false`.
  * `writer` {Function} The function to invoke to format the output of each
  command before writing to `output`. Defaults to [`util.inspect()`][].
+ * `completer` {Function} An optional function used for custom Tab auto
+ completion. See [`readline.InterfaceCompleter`][] for an example.
  * `replMode` - A flag that specifies whether the default evaluator executes
  all JavaScript commands in strict mode, default mode, or a hybrid mode
  ("magic" mode.) Acceptable values are:
@@ -526,3 +528,4 @@ see: https://gist.github.com/2053342
 [`util.inspect()`]: util.html#util_util_inspect_object_options
 [here]: util.html#util_custom_inspect_function_on_objects
 [`readline.Interface`]: readline.html#readline_class_interface
+[`readline.InterfaceCompleter`]: readline.html#readline_use_of_the_completer_function

lib/repl.js

@@ -386,14 +386,15 @@ function REPLServer(prompt,
  self.bufferedCommand = '';
  self.lines.level = [];
 
- function complete(text, callback) {
- self.complete(text, callback);
- }
+ // Figure out which "complete" function to use.
+ self.completer = (typeof options.completer === 'function')
+ ? options.completer
+ : complete;
 
  Interface.call(this, {
  input: self.inputStream,
  output: self.outputStream,
- completer: complete,
+ completer: self.completer,
  terminal: options.terminal,
  historySize: options.historySize,
  prompt
@@ -706,6 +707,10 @@ function filteredOwnPropertyNames(obj) {
  return Object.getOwnPropertyNames(obj).filter(intFilter);
 }
 
+REPLServer.prototype.complete = function() {
+ this.completer.apply(this, arguments);
+};
+
 // Provide a list of completions for the given leading text. This is
 // given to the readline interface for handling tab completion.
 //
@@ -716,7 +721,7 @@ function filteredOwnPropertyNames(obj) {
 //
 // Warning: This eval's code like "foo.bar.baz", so it will run property
 // getter code.
-REPLServer.prototype.complete = function(line, callback) {
+function complete(line, callback) {
  // There may be local variables to evaluate, try a nested REPL
  if (this.bufferedCommand !== undefined && this.bufferedCommand.length) {
  // Get a new array of inputed lines
@@ -975,7 +980,7 @@ REPLServer.prototype.complete = function(line, callback) {
 
  callback(null, [completions || [], completeOn]);
  }
-};
+}
 
 
 /**

test/parallel/test-repl-tab-complete.js

@@ -32,7 +32,7 @@ testMe.complete('console.lo', common.mustCall(function(error, data) {
  assert.deepStrictEqual(data, [['console.log'], 'console.lo']);
 }));
 
-// Tab Complete will return globaly scoped variables
+// Tab Complete will return globally scoped variables
 putIn.run(['};']);
 testMe.complete('inner.o', common.mustCall(function(error, data) {
  assert.deepStrictEqual(data, works);
@@ -283,3 +283,68 @@ if (typeof Intl === 'object') {
 testNonGlobal.complete('I', common.mustCall((error, data) => {
  assert.deepStrictEqual(data, builtins);
 }));
+
+// To test custom completer function.
+// Sync mode.
+const customCompletions = 'aaa aa1 aa2 bbb bb1 bb2 bb3 ccc ddd eee'.split(' ');
+const testCustomCompleterSyncMode = repl.start({
+ prompt: '',
+ input: putIn,
+ output: putIn,
+ completer: function completerSyncMode(line) {
+ const hits = customCompletions.filter((c) => {
+ return c.indexOf(line) === 0;
+ });
+ // Show all completions if none found.
+ return [hits.length ? hits : customCompletions, line];
+ }
+});
+
+// On empty line should output all the custom completions
+// without complete anything.
+testCustomCompleterSyncMode.complete('', common.mustCall((error, data) => {
+ assert.deepStrictEqual(data, [
+ customCompletions,
+ ''
+ ]);
+}));
+
+// On `a` should output `aaa aa1 aa2` and complete until `aa`.
+testCustomCompleterSyncMode.complete('a', common.mustCall((error, data) => {
+ assert.deepStrictEqual(data, [
+ 'aaa aa1 aa2'.split(' '),
+ 'a'
+ ]);
+}));
+
+// To test custom completer function.
+// Async mode.
+const testCustomCompleterAsyncMode = repl.start({
+ prompt: '',
+ input: putIn,
+ output: putIn,
+ completer: function completerAsyncMode(line, callback) {
+ const hits = customCompletions.filter((c) => {
+ return c.indexOf(line) === 0;
+ });
+ // Show all completions if none found.
+ callback(null, [hits.length ? hits : customCompletions, line]);
+ }
+});
+
+// On empty line should output all the custom completions
+// without complete anything.
+testCustomCompleterAsyncMode.complete('', common.mustCall((error, data) => {
+ assert.deepStrictEqual(data, [
+ customCompletions,
+ ''
+ ]);
+}));
+
+// On `a` should output `aaa aa1 aa2` and complete until `aa`.
+testCustomCompleterAsyncMode.complete('a', common.mustCall((error, data) => {
+ assert.deepStrictEqual(data, [
+ 'aaa aa1 aa2'.split(' '),
+ 'a'
+ ]);
+}));