Add typescript-eslint-language-service (#30015)

webapp/channels/tsconfig.json

@@ -26,7 +26,10 @@
     "paths": {
         "mattermost-redux/*": ["packages/mattermost-redux/src/*"],
         "@mui/styled-engine": ["./node_modules/@mui/styled-engine-sc"],
-    }
+    },
+    "plugins": [{
+        "name": "typescript-eslint-language-service"
+    }]
   },
   "include": [
     "./src/**/*",

webapp/channels/webpack.config.js

@@ -18,10 +18,14 @@ const packageJson = require('./package.json');
 
 const NPM_TARGET = process.env.npm_lifecycle_event;
 
+// list of known code editors that set an environment variable.
+const knownCodeEditors = ['VSCODE_CWD', 'INSIDE_EMACS'];
+const isInsideCodeEditor = knownCodeEditors.some((editor) => process.env[editor]);
+
 const targetIsRun = NPM_TARGET?.startsWith('run');
 const targetIsStats = NPM_TARGET === 'stats';
 const targetIsDevServer = NPM_TARGET?.startsWith('dev-server');
-const targetIsEslint = NPM_TARGET?.startsWith('check') || NPM_TARGET === 'fix' || process.env.VSCODE_CWD;
+const targetIsEslint = NPM_TARGET?.startsWith('check') || NPM_TARGET === 'fix' || isInsideCodeEditor;
 
 const DEV = targetIsRun || targetIsStats || targetIsDevServer;
 

webapp/package-lock.json

@@ -45,6 +45,7 @@
         "sass-loader": "16.0.2",
         "strip-ansi": "7.1.0",
         "style-loader": "4.0.0",
+        "typescript-eslint-language-service": "5.0.5",
         "webpack": "5.95.0",
         "webpack-cli": "5.1.4",
         "webpack-dev-server": "5.1.0"
@@ -27025,6 +27026,17 @@
         "node": ">=14.17"
       }
     },
+    "node_modules/typescript-eslint-language-service": {
+      "version": "5.0.5",
+      "resolved": "https://registry.npmjs.org/typescript-eslint-language-service/-/typescript-eslint-language-service-5.0.5.tgz",
+      "integrity": "sha512-b7gWXpwSTqMVKpPX3WttNZEyVAMKs/2jsHKF79H+qaD6mjzCyU5jboJe/lOZgLJD+QRsXCr0GjIVxvl5kI1NMw==",
+      "dev": true,
+      "peerDependencies": {
+        "@typescript-eslint/parser": ">= 5.0.0",
+        "eslint": ">= 8.0.0",
+        "typescript": ">= 4.0.0"
+      }
+    },
     "node_modules/ua-parser-js": {
       "version": "1.0.39",
       "resolved": "https://registry.npmjs.org/ua-parser-js/-/ua-parser-js-1.0.39.tgz",

webapp/package.json

@@ -50,6 +50,7 @@
     "sass-loader": "16.0.2",
     "strip-ansi": "7.1.0",
     "style-loader": "4.0.0",
+    "typescript-eslint-language-service": "5.0.5",
     "webpack": "5.95.0",
     "webpack-cli": "5.1.4",
     "webpack-dev-server": "5.1.0"