Breaking: remove deprecated experimentalObjectRestSpread option (#11420)

docs/user-guide/configuring.md

@@ -52,10 +52,6 @@ Here's an example `.eslintrc.json` file:
 
 Setting parser options helps ESLint determine what is a parsing error. All language options are `false` by default.
 
-### Deprecated
-
-* `ecmaFeatures.experimentalObjectRestSpread` - enable support for the experimental [object rest/spread properties](https://github.com/tc39/proposal-object-rest-spread). This syntax has been supported in `ecmaVersion: 2018`. This option will be removed in the future.
-
 ## Specifying Parser
 
 By default, ESLint uses [Espree](https://github.com/eslint/espree) as its parser. You can optionally specify that a different parser should be used in your configuration file so long as the parser meets the following requirements:

lib/config/config-validator.js

@@ -238,15 +238,6 @@ function validateConfigSchema(config, source = null) {
     if (Object.hasOwnProperty.call(config, "ecmaFeatures")) {
         emitDeprecationWarning(source, "ESLINT_LEGACY_ECMAFEATURES");
     }
-
-    if (
-        (config.parser || "espree") === "espree" &&
-        config.parserOptions &&
-        config.parserOptions.ecmaFeatures &&
-        config.parserOptions.ecmaFeatures.experimentalObjectRestSpread
-    ) {
-        emitDeprecationWarning(source, "ESLINT_LEGACY_OBJECT_REST_SPREAD");
-    }
 }
 
 /**

lib/linter.js

@@ -336,16 +336,6 @@ function resolveParserOptions(parserName, providedOptions, enabledEnvironments)
 
     mergedParserOptions.ecmaVersion = normalizeEcmaVersion(mergedParserOptions.ecmaVersion, isModule);
 
-    // TODO: For backward compatibility. Will remove on v6.0.0.
-    if (
-        parserName === DEFAULT_PARSER_NAME &&
-        mergedParserOptions.ecmaFeatures &&
-        mergedParserOptions.ecmaFeatures.experimentalObjectRestSpread &&
-        (!mergedParserOptions.ecmaVersion || mergedParserOptions.ecmaVersion < 9)
-    ) {
-        mergedParserOptions.ecmaVersion = 9;
-    }
-
     return mergedParserOptions;
 }
 

tests/lib/config.js

@@ -1397,74 +1397,6 @@ describe("Config", () => {
                         `The 'ecmaFeatures' config file property is deprecated, and has no effect. (found in "tests${path.sep}fixtures${path.sep}config-file${path.sep}ecma-features${path.sep}.eslintrc.yml")`
                     );
                 }));
-
-            it("should emit a deprecation warning if 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' is given.", () => Promise.resolve()
-                .then(() => {
-                    const cwd = path.resolve(__dirname, "../fixtures/config-file/experimental-object-rest-spread/basic/");
-                    const config = new Config({ cwd }, linter);
-
-                    config.getConfig("test.js");
-
-                    // Wait for "warning" event.
-                    return nextTick();
-                })
-                .then(() => {
-                    assert.notStrictEqual(warning, null);
-                    assert.strictEqual(
-                        warning.message,
-                        `The 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' option is deprecated. Use 'parserOptions.ecmaVersion' instead. (found in "tests${path.sep}fixtures${path.sep}config-file${path.sep}experimental-object-rest-spread${path.sep}basic${path.sep}.eslintrc.yml")`
-                    );
-                }));
-
-            it("should emit a deprecation warning if 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' is given in a parent config.", () => Promise.resolve()
-                .then(() => {
-                    const cwd = path.resolve(__dirname, "../fixtures/config-file/experimental-object-rest-spread/subdir/");
-                    const config = new Config({ cwd }, linter);
-
-                    config.getConfig("lib/test.js");
-
-                    // Wait for "warning" event.
-                    return nextTick();
-                })
-                .then(() => {
-                    assert.notStrictEqual(warning, null);
-                    assert.strictEqual(
-                        warning.message,
-                        `The 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' option is deprecated. Use 'parserOptions.ecmaVersion' instead. (found in "tests${path.sep}fixtures${path.sep}config-file${path.sep}experimental-object-rest-spread${path.sep}subdir${path.sep}.eslintrc.yml")`
-                    );
-                }));
-
-            it("should emit a deprecation warning if 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' is given in a shareable config.", () => Promise.resolve()
-                .then(() => {
-                    const cwd = path.resolve(__dirname, "../fixtures/config-file/experimental-object-rest-spread/extends/");
-                    const config = new Config({ cwd }, linter);
-
-                    config.getConfig("test.js");
-
-                    // Wait for "warning" event.
-                    return nextTick();
-                })
-                .then(() => {
-                    assert.notStrictEqual(warning, null);
-                    assert.strictEqual(
-                        warning.message,
-                        `The 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' option is deprecated. Use 'parserOptions.ecmaVersion' instead. (found in "tests${path.sep}fixtures${path.sep}config-file${path.sep}experimental-object-rest-spread${path.sep}extends${path.sep}common.yml")`
-                    );
-                }));
-
-            it("should NOT emit a deprecation warning even if 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' is given, if parser is not espree.", () => Promise.resolve()
-                .then(() => {
-                    const cwd = path.resolve(__dirname, "../fixtures/config-file/experimental-object-rest-spread/another-parser/");
-                    const config = new Config({ cwd }, linter);
-
-                    config.getConfig("test.js");
-
-                    // Wait for "warning" event.
-                    return nextTick();
-                })
-                .then(() => {
-                    assert.strictEqual(warning, null);
-                }));
         });
     });
 

tests/lib/linter.js

@@ -3545,15 +3545,6 @@ describe("Linter", () => {
             linter.verify("x", { rules: { "foo-bar-baz": "error" } });
             assert(spy.calledOnce);
         });
-
-        it("should parse ES2018 code for backward compatibility if 'parserOptions.ecmaFeatures.experimentalObjectRestSpread' is given.", () => {
-            const messages = linter.verify(
-                "async function* f() { let {a, ...rest} = { a, ...obj }; }",
-                { parserOptions: { ecmaFeatures: { experimentalObjectRestSpread: true } } }
-            );
-
-            assert(messages.length === 0);
-        });
     });
 
     describe("context.getScope()", () => {