Add support for HMR with elm-hot

parcel-bundler · Dec 8, 2018 · 72f10f9 · 72f10f9
1 parent d2dc7c9
commit 72f10f9
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Showing 2 changed files with 18 additions and 1 deletion.
diff --git a/src/assets/ElmAsset.js b/src/assets/ElmAsset.js
@@ -9,7 +9,6 @@ class ElmAsset extends Asset {
   constructor(name, options) {
     super(name, options);
     this.type = 'js';
-    this.hmrPageReload = true;
   }
 
   async parse() {
@@ -46,6 +45,10 @@ class ElmAsset extends Asset {
 
     let compiled = await this.elm.compileToString(this.name, options);
     this.contents = compiled.toString();
+    if (this.options.hmr) {
+      let {inject} = await localRequire('elm-hot', this.name);
+      this.contents = inject(this.contents);
+    }
   }
 
   async collectDependencies() {

diff --git a/test/elm.js b/test/elm.js
@@ -15,6 +15,20 @@ describe('elm', function() {
     assert.equal(typeof output().Elm.Main.init, 'function');
   });
 
+  it('should apply elm-hot if HMR is enabled', async function() {
+    let b = await bundle(__dirname + '/integration/elm/index.js', {
+      hmr: true
+    });
+
+    await assertBundleTree(b, {
+      type: 'js',
+      assets: ['Main.elm', 'hmr-runtime.js', 'index.js']
+    });
+
+    let js = await fs.readFile(__dirname + '/dist/index.js', 'utf8');
+    assert(js.includes('[elm-hot]'));
+  });
+
   it('should minify Elm in production mode', async function() {
     let b = await bundle(__dirname + '/integration/elm/index.js', {
       production: true