fix: don’t hook into ‘compile’ event when ‘shouldWatch’ is false

Author: chrisbreiding

index.js

@@ -149,20 +149,22 @@ const preprocessor = (options = {}) => {
       latestBundle = createDeferred()
       bundles[filePath] = latestBundle.promise.tap(() => {
         log('- compile finished for', filePath)
-        // when the bundling is finished, we call `util.fileUpdated`
-        // to let Cypress know to re-run the spec
+        // when the bundling is finished, emit 'rerun' to let Cypress
+        // know to rerun the spec
         file.emit('rerun')
       })
     }
 
-    if (compiler.hooks) {
-      compiler.hooks.compile.tap(plugin, onCompile)
-    } else {
-      compiler.plugin('compile', onCompile)
-    }
-
+    // when we should watch, we hook into the 'compile' hook so we know when
+    // to rerun the tests
     if (file.shouldWatch) {
       log('watching')
+
+      if (compiler.hooks) {
+        compiler.hooks.compile.tap(plugin, onCompile)
+      } else {
+        compiler.plugin('compile', onCompile)
+      }
     }
 
     const bundler = file.shouldWatch ? compiler.watch(watchOptions, handle) : compiler.run(handle)

test/index_spec.js

@@ -142,13 +142,23 @@ describe('webpack preprocessor', function () {
         })
       })
 
-      it('emits `rerun` when there is an update', function () {
+      it('emits "rerun" when shouldWatch is true and there is an update', function () {
+        this.file.shouldWatch = true
+        this.compilerApi.watch.yields(null, this.statsApi)
         this.compilerApi.plugin.withArgs('compile').yields()
         return this.run().then(() => {
           expect(this.file.emit).to.be.calledWith('rerun')
         })
       })
 
+      it('does not emit "rerun" when shouldWatch is false', function () {
+        this.file.shouldWatch = false
+        this.compilerApi.plugin.withArgs('compile').yields()
+        return this.run().then(() => {
+          expect(this.file.emit).not.to.be.calledWith('rerun')
+        })
+      })
+
       it('closes bundler when shouldWatch is true and `close` is emitted', function () {
         this.file.shouldWatch = true
         this.compilerApi.watch.yields(null, this.statsApi)