Warp up prettier-eslint worker with first available open document (#202)

.all-contributorsrc

@@ -53,6 +53,15 @@
         "code",
         "review"
       ]
+    },
+    {
+      "login": "netux",
+      "name": "Martín Rodríguez",
+      "avatar_url": "https://avatars.githubusercontent.com/u/6181929?v=4",
+      "profile": "https://netux.site/",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 7

README.md

@@ -1,7 +1,7 @@
 <img src="https://github.com/idahogurl/vs-code-prettier-eslint/blob/master/icon.png?raw=true" width="150">
 
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-4-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-5-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 # [VS Code Prettier ESLint](https://marketplace.visualstudio.com/items?itemName=rvest.vs-code-prettier-eslint)
@@ -168,6 +168,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
       <td align="center" valign="top" width="14.28%"><a href="https://github.com/tbekaert"><img src="https://avatars.githubusercontent.com/u/11920484?v=4?s=100" width="100px;" alt="Thomas Bekaert"/><br /><sub><b>Thomas Bekaert</b></sub></a><br /><a href="https://github.com/idahogurl/vs-code-prettier-eslint/commits?author=tbekaert" title="Code">💻</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://mattbrannon.dev/"><img src="https://avatars.githubusercontent.com/u/36570183?v=4?s=100" width="100px;" alt="Matt Brannon"/><br /><sub><b>Matt Brannon</b></sub></a><br /><a href="https://github.com/idahogurl/vs-code-prettier-eslint/commits?author=mattbrannon" title="Documentation">📖</a></td>
       <td align="center" valign="top" width="14.28%"><a href="https://www.1stg.me/"><img src="https://avatars.githubusercontent.com/u/8336744?v=4?s=100" width="100px;" alt="JounQin"/><br /><sub><b>JounQin</b></sub></a><br /><a href="https://github.com/idahogurl/vs-code-prettier-eslint/commits?author=JounQin" title="Code">💻</a> <a href="https://github.com/idahogurl/vs-code-prettier-eslint/pulls?q=is%3Apr+reviewed-by%3AJounQin" title="Reviewed Pull Requests">👀</a></td>
+      <td align="center" valign="top" width="14.28%"><a href="https://netux.site/"><img src="https://avatars.githubusercontent.com/u/6181929?v=4?s=100" width="100px;" alt="Martín Rodríguez"/><br /><sub><b>Martín Rodríguez</b></sub></a><br /><a href="https://github.com/idahogurl/vs-code-prettier-eslint/commits?author=netux" title="Code">💻</a></td>
     </tr>
   </tbody>
 </table>

package.json

@@ -44,7 +44,8 @@
     "onLanguage:typescript",
     "onLanguage:typescriptreact",
     "onLanguage:vue",
-    "onLanguage:yaml"
+    "onLanguage:yaml",
+    "onStartupFinished"
   ],
   "scripts": {
     "lint": "eslint . --ignore-pattern test/fixtures/",

src/extension.js

@@ -71,6 +71,44 @@ function formatter(document) {
   }
 }
 
+/**
+ * Provides a promise that resolves as soon as there is an active text editor
+ * with a document open on a language this extension supports.
+ *
+ * @returns {Promise<TextDocument>}
+ */
+function waitForActiveSupportedDocument() {
+  if (!window.activeTextEditor || !supportedLanguages.includes(window.activeTextEditor.document.languageId)) {
+    return new Promise((resolve) => {
+      const handler = window.onDidChangeActiveTextEditor(({ document }) => {
+        if (supportedLanguages.includes(document.languageId)) {
+          handler.dispose();
+          resolve(document);
+        }
+      });
+    })
+  }
+
+  return Promise.resolve(window.activeTextEditor.document);
+}
+
+/**
+ * Warms up the worker by running 'prettier-eslint' with some dummy data.
+ *
+ * @param {TextDocument} document - Used to resolve 'prettier-eslint', as well as needed
+ * by 'prettier-eslint' to resolve its internal dependencies (eslint and prettier).
+ */
+async function warmUpWorker(document) {
+  const prettierEslintPath = getModulePath(document.fileName, 'prettier-eslint');
+
+  formatText({
+    text: '',
+    prettierEslintPath,
+    filePath: document.fileName,
+  });
+}
+
+
 const supportedLanguages = [
   'css',
   'graphql',
@@ -97,3 +135,12 @@ supportedLanguages.forEach((language) => {
     },
   });
 });
+
+waitForActiveSupportedDocument()
+  .then((document) => warmUpWorker(document))
+  .then(() => {
+    outputChannel.appendLine('Worker has been warmed up');
+  })
+  .catch((error) => {
+      outputChannel.appendLine('Error: Could not warm up worker. Formatting a file for the first time may take longer than usual.\nStacktrace: ' + error.stack);
+  });