Support --ignore-pattern as a command line option

docs/cli.md

@@ -114,6 +114,14 @@ If you don’t have a configuration file, or want to ignore it if it does exist,
 
 Path to a file containing patterns that describe files to ignore. By default, Prettier looks for `./.prettierignore`.
 
+## `--ignore-pattern`
+
+This allows you to specify patterns of files to ignore (in addition to those in .prettierignore).
+
+```bash
+prettier --ignore-pattern "./ignore**.js" --check .
+```
+
 ## `--list-different`
 
 Another useful flag is `--list-different` (or `-l`) which prints the filenames of files that are different from Prettier formatting. If there are differences the script errors out, which is useful in a CI scenario.

src/cli/format.js

@@ -233,7 +233,8 @@ async function createIgnorerFromContextOrDie(context) {
   try {
     return await createIgnorer(
       context.argv.ignorePath,
-      context.argv.withNodeModules
+      context.argv.withNodeModules,
+      context.argv.ignorePatterns
     );
   } catch (e) {
     context.logger.error(e.message);

src/common/create-ignorer.js

@@ -7,32 +7,40 @@ const getFileContentOrNull = require("../utils/get-file-content-or-null.js");
 /**
  * @param {string?} ignorePath
  * @param {boolean?} withNodeModules
+ * @param {Array<string>?} ignorePatterns
  */
-async function createIgnorer(ignorePath, withNodeModules) {
+async function createIgnorer(ignorePath, withNodeModules, ignorePatterns = []) {
   const ignoreContent = ignorePath
     ? await getFileContentOrNull(path.resolve(ignorePath))
     : null;
 
-  return _createIgnorer(ignoreContent, withNodeModules);
+  return _createIgnorer(ignoreContent, withNodeModules, ignorePatterns);
 }
 
 /**
  * @param {string?} ignorePath
  * @param {boolean?} withNodeModules
  */
-createIgnorer.sync = function (ignorePath, withNodeModules) {
+createIgnorer.sync = function (
+  ignorePath,
+  withNodeModules,
+  ignorePatterns = []
+) {
   const ignoreContent = !ignorePath
     ? null
     : getFileContentOrNull.sync(path.resolve(ignorePath));
-  return _createIgnorer(ignoreContent, withNodeModules);
+  return _createIgnorer(ignoreContent, withNodeModules, ignorePatterns);
 };
 
 /**
  * @param {null | string} ignoreContent
  * @param {boolean?} withNodeModules
+ * @param {Array<string>} ignorePatterns
  */
-function _createIgnorer(ignoreContent, withNodeModules) {
+function _createIgnorer(ignoreContent, withNodeModules, ignorePatterns) {
   const ignorer = ignore({ allowRelativePaths: true }).add(ignoreContent || "");
+  ignorer.add(ignorePatterns);
+
   if (!withNodeModules) {
     ignorer.add("node_modules");
   }

src/main/core-options.js

@@ -104,6 +104,21 @@ const options = {
     cliCategory: CATEGORY_OTHER,
     cliDescription: "Path to the file to pretend that stdin comes from.",
   },
+  ignorePatterns: {
+    since: "2.9.0",
+    type: "path",
+    array: true,
+    default: [{ value: [] }],
+    category: CATEGORY_GLOBAL,
+    description: outdent`
+      Specify the patterns of files to ignore, in addition to those in the
+      configuration.
+    `,
+    exception: (value) =>
+      typeof value === "string" || typeof value === "object",
+    cliName: "ignore-pattern",
+    cliCategory: CATEGORY_CONFIG,
+  },
   insertPragma: {
     since: "1.8.0",
     category: CATEGORY_SPECIAL,

tests/integration/__tests__/__snapshots__/early-exit.js.snap

@@ -114,6 +114,9 @@ Config options:
                            Find and print the path to a configuration file for the given input file.
   --ignore-path <path>     Path to a file with patterns describing files to ignore.
                            Defaults to .prettierignore.
+  --ignore-pattern <path>  Specify the patterns of files to ignore, in addition to those in the
+                           configuration.
+                           Defaults to [].
   --plugin <path>          Add a plugin. Multiple plugins can be passed as separate \`--plugin\`s.
                            Defaults to [].
   --plugin-search-dir <path>
@@ -289,6 +292,9 @@ Config options:
                            Find and print the path to a configuration file for the given input file.
   --ignore-path <path>     Path to a file with patterns describing files to ignore.
                            Defaults to .prettierignore.
+  --ignore-pattern <path>  Specify the patterns of files to ignore, in addition to those in the
+                           configuration.
+                           Defaults to [].
   --plugin <path>          Add a plugin. Multiple plugins can be passed as separate \`--plugin\`s.
                            Defaults to [].
   --plugin-search-dir <path>

tests/integration/__tests__/__snapshots__/help-options.js.snap

@@ -274,6 +274,20 @@ Default: .prettierignore
 
 exports[`show detailed usage with --help ignore-path (write) 1`] = `[]`;
 
+exports[`show detailed usage with --help ignore-pattern (stderr) 1`] = `""`;
+
+exports[`show detailed usage with --help ignore-pattern (stdout) 1`] = `
+"--ignore-pattern <path>
+
+  Specify the patterns of files to ignore, in addition to those in the
+  configuration.
+
+Default: []
+"
+`;
+
+exports[`show detailed usage with --help ignore-pattern (write) 1`] = `[]`;
+
 exports[`show detailed usage with --help ignore-unknown (stderr) 1`] = `""`;
 
 exports[`show detailed usage with --help ignore-unknown (stdout) 1`] = `

tests/integration/__tests__/__snapshots__/ignore-patterns.js.snap

@@ -0,0 +1,25 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`ignore patterns (stderr) 1`] = `""`;
+
+exports[`ignore patterns (stdout) 1`] = `
+"regular-module.js
+"
+`;
+
+exports[`ignore patterns (write) 1`] = `[]`;
+
+exports[`ignore patterns with multiple arguments (stderr) 1`] = `""`;
+
+exports[`ignore patterns with multiple arguments (stdout) 1`] = `""`;
+
+exports[`ignore patterns with multiple arguments (write) 1`] = `[]`;
+
+exports[`outputs files as-is if no --write (stderr) 1`] = `""`;
+
+exports[`outputs files as-is if no --write (stdout) 1`] = `
+"'use strict';
+"
+`;
+
+exports[`outputs files as-is if no --write (write) 1`] = `[]`;

tests/integration/__tests__/__snapshots__/schema.js.snap

@@ -118,6 +118,15 @@ This option cannot be used with --range-start and --range-end.",
             },
           ],
         },
+        "ignorePatterns": {
+          "default": [],
+          "description": "Specify the patterns of files to ignore, in addition to those in the
+configuration.",
+          "items": {
+            "type": "string",
+          },
+          "type": "array",
+        },
         "insertPragma": {
           "default": false,
           "description": "Insert @format pragma into file's first docblock comment.",

tests/integration/__tests__/__snapshots__/support-info.js.snap

@@ -143,6 +143,10 @@ exports[`API getSupportInfo() 1`] = `
       "default": "css",
       "type": "choice",
     },
+    "ignorePatterns": {
+      "default": [],
+      "type": "path",
+    },
     "insertPragma": {
       "default": false,
       "type": "boolean",
@@ -912,6 +916,16 @@ exports[`CLI --support-info (stdout) 1`] = `
       "since": "1.15.0",
       "type": "choice"
     },
+    {
+      "array": true,
+      "category": "Global",
+      "default": [],
+      "description": "Specify the patterns of files to ignore, in addition to those in the\\nconfiguration.",
+      "name": "ignorePatterns",
+      "pluginDefaults": {},
+      "since": "2.9.0",
+      "type": "path"
+    },
     {
       "category": "Special",
       "default": false,

tests/integration/__tests__/ignore-patterns.js

@@ -0,0 +1,39 @@
+"use strict";
+
+const runPrettier = require("../run-prettier.js");
+
+describe("ignore patterns", () => {
+  runPrettier("cli/ignore-patterns", [
+    "**/*.js",
+    "--ignore-pattern",
+    "**/other-regular-module.js",
+    "-l",
+  ]).test({
+    status: 1,
+  });
+});
+
+describe("ignore patterns with multiple arguments", () => {
+  runPrettier("cli/ignore-patterns", [
+    "**/*.js",
+    "--ignore-pattern",
+    "**/other-regular-module.js",
+    "--ignore-pattern",
+    "**/regular-module.js",
+    "-l",
+  ]).test({
+    status: 0,
+  });
+});
+
+describe("outputs files as-is if no --write", () => {
+  runPrettier(
+    "cli/ignore-patterns",
+    ["--ignore-pattern", "**/regular-module.js", "regular-module.js"],
+    {
+      ignoreLineEndings: true,
+    }
+  ).test({
+    status: 0,
+  });
+});

tests/integration/cli/ignore-patterns/other-regular-module.js

@@ -0,0 +1 @@
+'use strict';

tests/integration/cli/ignore-patterns/regular-module.js

@@ -0,0 +1 @@
+'use strict';