generatorStarSpacing option

corresponding to eslint generator-star-spacing option

tested with and without space-before-function-paren enabled

as needed for consistency with standard & semistandard

based on proposal in prettier#5723

Co-authored-by: Christopher J. Brody <chris.brody@gmail.com>
Co-authored-by: Adam Stankiewicz <sheerun@sher.pl>
Co-authored-by: Joseph Frazier <1212jtraceur@gmail.com>
Co-authored-by: Rafael Hengles <rafael@hengles.net>
Co-authored-by: Ika <ikatyang@gmail.com>
Co-authored-by: Lucas Azzola <derflatulator@gmail.com>

README.md

@@ -22,6 +22,7 @@ prettierx <options> <file(s)>
 | Option                            | Default value | CLI Override                    | API Override                       | Description                              |
 | --------------------------------- | ------------- | ------------------------------- | ---------------------------------- | ---------------------------------------- |
 | Space before function parentheses | `false`       | `--space-before-function-paren` | `spaceBeforeFunctionParen: <bool>` | Put a space before function parenthesis. |
+| Spaces around the star (\*\) in generator functions | `false`       | `--generator-star-spacing` | `generatorStarSpacing: <bool>` | Add spaces around the star (\*\) in generator functions (before and after - from eslint). |
 
 <!-- - FUTURE TBD prettierx vs prettier (???):
 ![Prettier Banner](https://raw.githubusercontent.com/prettier/prettier-logo/master/images/prettier-banner-light.png)

docs/options.md

@@ -178,6 +178,14 @@ Put a space before function parenthesis.
 | ------- | ------------------------------- | ---------------------------------- |
 | `false` | `--space-before-function-paren` | `spaceBeforeFunctionParen: <bool>` |
 
+## Generator star spacing
+
+Add spaces around the star (\*\) in generator functions (before and after - from eslint).
+
+| Default | CLI Override                    | API Override                       |
+| ------- | ------------------------------- | ---------------------------------- |
+| `false` | `--generator-star-spacing`      | `generatorStarSpacing: <bool>`     |
+
 ## Parser
 
 Specify which parser to use.

src/language-js/options.js

@@ -40,6 +40,13 @@ module.exports = {
     oppositeDescription:
       "Do not print semicolons, except at the beginning of lines which may need them."
   },
+  generatorStarSpacing: {
+    category: CATEGORY_JAVASCRIPT,
+    type: "boolean",
+    default: false,
+    description:
+      "Add spaces around the star ('*') in generator functions (before and after - from eslint)."
+  },
   spaceBeforeFunctionParen: {
     category: CATEGORY_JAVASCRIPT,
     type: "boolean",

src/language-js/printer-estree.js

@@ -3723,6 +3723,9 @@ function printMethod(path, options, print) {
   if (!kind || kind === "init" || kind === "method" || kind === "constructor") {
     if (node.value.generator) {
       parts.push("*");
+      if (options.generatorStarSpacing) {
+        parts.push(" ");
+      }
     }
   } else {
     assert.ok(kind === "get" || kind === "set");
@@ -4226,6 +4229,9 @@ function printFunctionDeclaration(path, print, options) {
   parts.push("function");
 
   if (n.generator) {
+    if (options.generatorStarSpacing) {
+      parts.push(" ");
+    }
     parts.push("*");
   }
   if (n.id) {
@@ -4236,7 +4242,10 @@ function printFunctionDeclaration(path, print, options) {
     printFunctionTypeParameters(path, options, print),
     group(
       concat([
-        options.spaceBeforeFunctionParen ? " " : "",
+        options.spaceBeforeFunctionParen ||
+        (options.generatorStarSpacing && !n.id)
+          ? " "
+          : "",
         printFunctionParams(path, print, options),
         printReturnType(path, print, options)
       ])
@@ -4257,6 +4266,9 @@ function printObjectMethod(path, options, print) {
   }
   if (objMethod.generator) {
     parts.push("*");
+    if (options.generatorStarSpacing) {
+      parts.push(" ");
+    }
   }
   if (
     objMethod.method ||

tests/generator-star-spacing/__snapshots__/jsfmt.spec.js.snap

@@ -0,0 +1,147 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`correct.js 1`] = `
+====================================options=====================================
+generatorStarSpacing: true
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+// correct for:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// but *not* for the following standard.js rules:
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function * generator() {}
+var anonymous = function * () {};
+var shorthand = { * generator() {} };
+class Example {
+  async * foo() {}
+}
+
+=====================================output=====================================
+// correct for:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// but *not* for the following standard.js rules:
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function * generator() {}
+var anonymous = function * () {};
+var shorthand = { * generator() {} };
+class Example {
+  async * foo() {}
+}
+
+================================================================================
+`;
+
+exports[`correct.js 2`] = `
+====================================options=====================================
+generatorStarSpacing: true
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+spaceBeforeFunctionParen: true
+                                                                                | printWidth
+=====================================input======================================
+// correct for:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// but *not* for the following standard.js rules:
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function * generator() {}
+var anonymous = function * () {};
+var shorthand = { * generator() {} };
+class Example {
+  async * foo() {}
+}
+
+=====================================output=====================================
+// correct for:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// but *not* for the following standard.js rules:
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function * generator () {}
+var anonymous = function * () {};
+var shorthand = { * generator () {} };
+class Example {
+  async * foo () {}
+}
+
+================================================================================
+`;
+
+exports[`incorrect.js 1`] = `
+====================================options=====================================
+generatorStarSpacing: true
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+                                                                                | printWidth
+=====================================input======================================
+// *incorrect* for the following standard.js rules:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function* generator() {}
+var anonymous = function* () {};
+var shorthand = { * generator() {} };
+function *generator() {}
+var anonymous = function *() {};
+var shorthand = { *generator() {} };
+
+=====================================output=====================================
+// *incorrect* for the following standard.js rules:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function * generator() {}
+var anonymous = function * () {};
+var shorthand = { * generator() {} };
+function * generator() {}
+var anonymous = function * () {};
+var shorthand = { * generator() {} };
+
+================================================================================
+`;
+
+exports[`incorrect.js 2`] = `
+====================================options=====================================
+generatorStarSpacing: true
+parsers: ["babel", "flow", "typescript"]
+printWidth: 80
+spaceBeforeFunctionParen: true
+                                                                                | printWidth
+=====================================input======================================
+// *incorrect* for the following standard.js rules:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function* generator() {}
+var anonymous = function* () {};
+var shorthand = { * generator() {} };
+function *generator() {}
+var anonymous = function *() {};
+var shorthand = { *generator() {} };
+
+=====================================output=====================================
+// *incorrect* for the following standard.js rules:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function * generator () {}
+var anonymous = function * () {};
+var shorthand = { * generator () {} };
+function * generator () {}
+var anonymous = function * () {};
+var shorthand = { * generator () {} };
+
+================================================================================
+`;

tests/generator-star-spacing/correct.js

@@ -0,0 +1,12 @@
+// correct for:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// but *not* for the following standard.js rules:
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function * generator() {}
+var anonymous = function * () {};
+var shorthand = { * generator() {} };
+class Example {
+  async * foo() {}
+}

tests/generator-star-spacing/incorrect.js

@@ -0,0 +1,11 @@
+// *incorrect* for the following standard.js rules:
+// * "generator-star-spacing": [ "error", { "before": true, "after": true } ],
+// * "space-before-function-paren": [ "error", "always" ],
+// * "semi": [ "error", "never" ],
+
+function* generator() {}
+var anonymous = function* () {};
+var shorthand = { * generator() {} };
+function *generator() {}
+var anonymous = function *() {};
+var shorthand = { *generator() {} };

tests/generator-star-spacing/jsfmt.spec.js

@@ -0,0 +1,7 @@
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  generatorStarSpacing: true
+});
+run_spec(__dirname, ["babel", "flow", "typescript"], {
+  generatorStarSpacing: true,
+  spaceBeforeFunctionParen: true
+});

tests_integration/__tests__/__snapshots__/early-exit.js.snap

@@ -65,6 +65,8 @@ Format options:
   --end-of-line <auto|lf|crlf|cr>
                            Which end of line characters to apply.
                            Defaults to auto.
+  --generator-star-spacing Add spaces around the star ('*') in generator functions (before and after - from eslint).
+                           Defaults to false.
   --html-whitespace-sensitivity <css|strict|ignore>
                            How to handle whitespaces in HTML.
                            Defaults to css.
@@ -217,6 +219,8 @@ Format options:
   --end-of-line <auto|lf|crlf|cr>
                            Which end of line characters to apply.
                            Defaults to auto.
+  --generator-star-spacing Add spaces around the star ('*') in generator functions (before and after - from eslint).
+                           Defaults to false.
   --html-whitespace-sensitivity <css|strict|ignore>
                            How to handle whitespaces in HTML.
                            Defaults to css.

tests_integration/__tests__/__snapshots__/help-options.js.snap

@@ -159,6 +159,19 @@ exports[`show detailed usage with --help find-config-path (stdout) 1`] = `
 
 exports[`show detailed usage with --help find-config-path (write) 1`] = `Array []`;
 
+exports[`show detailed usage with --help generator-star-spacing (stderr) 1`] = `""`;
+
+exports[`show detailed usage with --help generator-star-spacing (stdout) 1`] = `
+"--generator-star-spacing
+
+  Add spaces around the star ('*') in generator functions (before and after - from eslint).
+
+Default: false
+"
+`;
+
+exports[`show detailed usage with --help generator-star-spacing (write) 1`] = `Array []`;
+
 exports[`show detailed usage with --help help (stderr) 1`] = `""`;
 
 exports[`show detailed usage with --help help (stdout) 1`] = `

tests_integration/__tests__/__snapshots__/plugin-options.js.snap

@@ -13,11 +13,11 @@ exports[` 1`] = `
                              Defaults to auto.
 +   --foo-option <bar|baz>   foo description
 +                            Defaults to bar.
+    --generator-star-spacing Add spaces around the star ('*') in generator functions (before and after - from eslint).
+                             Defaults to false.
     --html-whitespace-sensitivity <css|strict|ignore>
                              How to handle whitespaces in HTML.
-                             Defaults to css.
-    --jsx-bracket-same-line  Put > on the last line instead of at a new line.
-                             Defaults to false."
+                             Defaults to css."
 `;
 
 exports[`show detailed external option with \`--help foo-option\` (stderr) 1`] = `""`;

tests_integration/__tests__/__snapshots__/schema.js.snap

@@ -79,6 +79,11 @@ This option cannot be used with --range-start and --range-end.",
           "description": "Specify the input filepath. This will be used to do parser inference.",
           "type": "string",
         },
+        "generatorStarSpacing": Object {
+          "default": false,
+          "description": "Add spaces around the star ('*') in generator functions (before and after - from eslint).",
+          "type": "boolean",
+        },
         "htmlWhitespaceSensitivity": Object {
           "default": "css",
           "description": "How to handle whitespaces in HTML.",

tests_integration/__tests__/__snapshots__/support-info.js.snap

@@ -108,6 +108,10 @@ Object {
       "default": undefined,
       "type": "path",
     },
+    "generatorStarSpacing": Object {
+      "default": false,
+      "type": "boolean",
+    },
     "htmlWhitespaceSensitivity": Object {
       "choices": Array [
         "css",
@@ -725,6 +729,14 @@ exports[`CLI --support-info (stdout) 1`] = `
       \\"since\\": \\"1.4.0\\",
       \\"type\\": \\"path\\"
     },
+    {
+      \\"category\\": \\"JavaScript\\",
+      \\"default\\": false,
+      \\"description\\": \\"Add spaces around the star ('*') in generator functions (before and after - from eslint).\\",
+      \\"name\\": \\"generatorStarSpacing\\",
+      \\"pluginDefaults\\": {},
+      \\"type\\": \\"boolean\\"
+    },
     {
       \\"category\\": \\"HTML\\",
       \\"choices\\": [