Ensure that the webpack output filename ends with .js.

This ensures that the Webpack SourceMapDevToolPlugin can handle the file, even when it has been originally no javascript file (e.g. .ts or .feature).

Author: jp7677

index.js

@@ -83,7 +83,7 @@ const preprocessor = (options = {}) => {
       entry,
       output: {
         path: path.dirname(outputPath),
-        filename: path.basename(outputPath),
+        filename: `${path.basename(outputPath, '.js')}.js`,
       },
     })
 

test/unit/index.spec.js

@@ -132,6 +132,17 @@ describe('webpack preprocessor', function () {
         })
       })
 
+      it('adds .js extension to filename when the originating file had been no javascript file', function () {
+        this.file.outputPath = 'output/output.ts'
+
+        return this.run().then(() => {
+          expect(webpack.lastCall.args[0].output).to.eql({
+            path: 'output',
+            filename: 'output.ts.js',
+          })
+        })
+      })
+
       it('enables inline source maps', function () {
         return this.run().then(() => {
           expect(webpack.lastCall.args[0].devtool).to.equal('inline-source-map')