Support absolute path in config file (#15666)

changelog_unreleased/api/15666.md

@@ -0,0 +1,15 @@
+#### Support absolute path as plugin in config file (#15666 by @fisker)
+
+```js
+// prettier.config.cjs
+module.exports = {
+  plugins: [
+    // posix style
+    "/path/to/plugin.js",
+    // Windows style
+    "D:\\\\path\\to\\plugin.js",
+    // Use `require.resolve`
+    require.resolve("my-awesome-prettier-plugin"),
+  ],
+};
+```

src/main/plugins/load-plugin.js

@@ -16,6 +16,10 @@ const loadPluginFromDirectory = mem(
 );
 
 const importPlugin = mem(async (name) => {
+  if (path.isAbsolute(name)) {
+    return import(pathToFileURL(name).href);
+  }
+
   try {
     // try local files
     return await import(pathToFileURL(path.resolve(name)).href);

tests/integration/__tests__/plugin-resolution.js

@@ -62,3 +62,14 @@ describe("loads --plugin by bespoke plugin name (assuming it is installed in cwd
     write: [],
   });
 });
+
+describe.only("support absolute path in config file", () => {
+  runCli("cli/config/plugins/absolute-path", ["--parser=uppercase-rocks"], {
+    input: "prettier should be uppercase",
+  }).test({
+    stdout: "PRETTIER SHOULD BE UPPERCASE",
+    stderr: "",
+    status: 0,
+    write: [],
+  });
+});

tests/integration/cli/config/plugins/absolute-path/prettier.config.mjs

@@ -0,0 +1,7 @@
+import path from 'node:path'
+
+export default {
+  plugins: [
+    path.resolve('../../../../../config/prettier-plugins/prettier-plugin-uppercase-rocks/index.js')
+  ]
+}