FIREFLY-2112: Add ESLint workflow and initial config

.github/workflows/lint.yml

@@ -0,0 +1,30 @@
+name: ESLint
+
+on:
+  pull_request:
+    branches: [dev]
+
+permissions:
+  contents: read
+
+concurrency:
+  group: eslint-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  eslint:
+    name: eslint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+
+      - uses: actions/setup-node@v5
+        with:
+          node-version: 26  # matches docker/Dockerfile (nodesource setup_26.x)
+          cache: yarn       # yarn.lock lives at the repo root
+
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile --ignore-platform
+
+      - name: Run ESLint
+        run: npx eslint .

eslint.config.mjs

@@ -1,3 +1,4 @@
+import js from "@eslint/js";
 import react from "eslint-plugin-react";
 import jsdoc from "eslint-plugin-jsdoc";
 import reactHooks from "eslint-plugin-react-hooks";
@@ -19,6 +20,16 @@ const gitIgnorePath = path.resolve(__dirname, ".gitignore")
 
 export default [
     includeIgnoreFile(gitIgnorePath), //ignore git-ignored dirs/files
+
+    // vendored third-party source
+    {ignores: [
+        "src/firefly/html/gpu-browser.min-*.js",
+        "src/firefly/js/externalSource/**",
+    ]},
+
+    // eslint's recommended rules; the block below layers over these
+    {files: ["**/*.js", "**/*.jsx"], ...js.configs.recommended},
+
     {
         files: ["**/*.js", "**/*.jsx"],
 
@@ -59,21 +70,41 @@ export default [
             eqeqeq: 1,
             "no-console": 0,
             "no-empty": 1,
-            "no-undef": 2,
             "no-use-before-define": 0,
             "no-unused-vars": 1,
             "object-shorthand": 1,
             "prefer-const": 1,
             "prefer-spread": 1,
             "prefer-template": 0,
+
+            // rules with existing violations: warn until the sites are addressed
+            "no-case-declarations": 1,
+            "no-async-promise-executor": 1,
+            "no-cond-assign": 1,
+            "no-constant-binary-expression": 1,
+            "no-control-regex": 1,
+            "no-debugger": 1,
+            "no-empty-pattern": 1,
+            "no-extra-boolean-cast": 1,
+            "no-import-assign": 1,
+            "no-irregular-whitespace": 1,
+            "no-prototype-builtins": 1,
+            "no-redeclare": 1,
+            "no-regex-spaces": 1,
+            "no-sparse-arrays": 1,
+            "no-undef": 1,
+            "no-unreachable": 1,
+            "no-unsafe-optional-chaining": 1,
+            "no-useless-escape": 1,
+            "@stylistic/js/semi": [1, "always"],   // restore to [2, "always"]
+
             "@stylistic/js/arrow-parens": [2, "always"],
             "@stylistic/js/comma-spacing": 0,
             "@stylistic/js/jsx-quotes": [1, "prefer-single"],
             "@stylistic/js/key-spacing": 0,
             "@stylistic/js/no-multi-spaces": 0,
-            "@stylistic/js/semi": [2, "always"],
             "@stylistic/js/space-infix-ops": 0,
-            "@stylistic/js/quotes": [2, "single", "avoid-escape"],
+            "@stylistic/js/quotes": [2, "single", {avoidEscape: true, allowTemplateLiterals: "avoidEscape"}],
             "react/jsx-boolean-value": [1, "always"],
             "react/jsx-no-duplicate-props": 1,
             "react/jsx-no-undef": 1,
@@ -108,13 +139,13 @@ export default [
             'react-hooks/unsupported-syntax': 'warn',
             'react-hooks/use-memo': 'warn',
             'react-hooks/incompatible-library': 'warn',
-            "jsdoc/check-param-names": 2,
+            "jsdoc/check-param-names": 1,
             "jsdoc/check-tag-names": 0,
             "jsdoc/check-types": 0,
             "jsdoc/newline-after-description": 0,
             "jsdoc/require-description-complete-sentence": 0,
             "jsdoc/require-hyphen-before-param-description": 0,
-            "jsdoc/require-param": 2,
+            "jsdoc/require-param": 1,
             "jsdoc/require-param-description": 0,
             "jsdoc/require-param-type": 0,
             "jsdoc/require-returns-description": 0,

package.json

@@ -65,6 +65,7 @@
     "@babel/preset-react": "^7.24.7",
     "@babel/register": "^7.24.6",
     "@eslint/compat": "^1.1.0",
+    "@eslint/js": "~9.38",
     "@stylistic/eslint-plugin-js": "~4.4",
     "@svgr/webpack": "^8.1.0",
     "@testing-library/dom": "^10",

yarn.lock

@@ -1422,7 +1422,7 @@
     minimatch "^3.1.2"
     strip-json-comments "^3.1.1"
 
-"@eslint/js@9.38.0":
+"@eslint/js@9.38.0", "@eslint/js@~9.38":
   version "9.38.0"
   resolved "https://registry.yarnpkg.com/@eslint/js/-/js-9.38.0.tgz#f7aa9c7577577f53302c1d795643589d7709ebd1"
   integrity sha512-UZ1VpFvXf9J06YG9xQBdnzU+kthors6KjhMAl6f4gH4usHyh31rUf2DLGInT8RFYIReYXNSydgPY0V2LuWgl7A==