Merge pull request #37 from guardian/add-eslint-config

Add eslint config

.editorconfig

@@ -1,16 +1,28 @@
-; This file is for unifying the coding style for different editors and IDEs
-; See editorconfig.org
+# based on https://github.com/guardian/configs/blob/main/.editorconfig
 
 ; top-most EditorConfig file
 root = true
 
 [*]
-indent_style = space
+# For [accessibility reasons](https://alexandersandberg.com/tabs-for-accessibility/)
+indent_style = tab
 indent_size = 4
 end_of_line = lf
 charset = utf-8
 trim_trailing_whitespace = true
 insert_final_newline = true
 
 [package.json]
-indent_size = 2
+# `npm` autoformats `package.json` every time you install a new dependency.
+indent_size = 2
+
+# Because `yml`
+[*.yml]
+indent_style = space
+indent_size = 2
+
+[*.md]
+# Using tabs to indent pre-formatted code in markdown makes the spacing too extreme
+# when rendered on GitHub, so we revert back to spaces here.
+indent_style = space
+indent_size = 4

.eslintrc.json

@@ -0,0 +1,13 @@
+{
+  "root": true,
+  "env": {
+    "jest": true,
+    "browser": true,
+    "node": true
+  },
+  "parserOptions": {
+    "sourceType": "module"
+  },
+  "extends": ["@guardian/eslint-config-typescript"],
+  "ignorePatterns": ["/dist"]
+}

.github/workflows/CI.yml

@@ -0,0 +1,26 @@
+name: CI
+on: push
+
+jobs:
+  lint:
+    name: Linting
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v2
+
+      # based on https://github.com/actions/setup-node/issues/32#issuecomment-539794249
+      - name: Read .nvmrc
+        run: echo ::set-output name=NVMRC::$(cat .nvmrc)
+        id: nvm
+
+      - name: Setup node
+        uses: actions/setup-node@v2.1.2
+        with:
+          node-version: '${{ steps.nvm.outputs.NVMRC }}'
+
+      - name: Install dependencies
+        uses: bahmutov/npm-install@v1
+
+      - name: Lint files
+        run: npm run lint

.nvmrc

@@ -0,0 +1 @@
+14.15.0

.prettierrc

@@ -0,0 +1 @@
+"@guardian/prettier"