Add linting and formatting for JS code in wasmtime explore (#8675)

.github/workflows/main.yml

@@ -55,6 +55,20 @@ jobs:
       env:
         GH_TOKEN: ${{ github.token }}
 
+  # Quick JS formatting/linting checks for the little bits of JS we have for the
+  # `wasmtime explore` UI.
+  check_js:
+    name: Check JS
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - run: npm install
+      working-directory: ./crates/explorer
+    - run: npm run lint
+      working-directory: ./crates/explorer
+    - run: npm run fmt-check
+      working-directory: ./crates/explorer
+
   # Check Code style quickly by running `clang-format` over all the C/C++ code
   #
   # Note that `wasmtime-platform.h` is excluded here as it's auto-generated.

.gitignore

@@ -23,3 +23,4 @@ vendor
 examples/build
 examples/.cache
 *.coredump
+crates/explorer/node_modules

crates/explorer/.prettierignore

@@ -0,0 +1,6 @@
+*.html
+*.css
+*.toml
+*.rs
+*.yml
+

crates/explorer/.prettierrc

@@ -0,0 +1,3 @@
+{
+  "arrowParens": "avoid"
+}

crates/explorer/eslint.config.js

@@ -0,0 +1,12 @@
+import js from "@eslint/js";
+
+export default [
+  js.configs.recommended,
+
+  {
+    rules: {
+      "no-unused-vars": "error",
+      "no-undef": "error",
+    },
+  },
+];