Fix for file with comments at end (grafana#853)

Previously if a script was ending in a comment or babel transforms it in
a way that it ends in comment it might also not have new line. In this
case if the files is compiled as import it would fail because imports
get a closure around it which was added without newlines :(.

js/bundle.go

@@ -142,11 +142,11 @@ func NewBundleFromArchive(arc *lib.Archive, rtOpts lib.RuntimeOptions) (*Bundle,
 		return nil, errors.Errorf("expected bundle type 'js', got '%s'", arc.Type)
 	}
 
-	initctx := NewInitContext(goja.New(), compiler, new(context.Context), arc.FS, arc.Pwd)
-	pgm, err := initctx.compileImport(string(arc.Data), arc.Filename)
+	pgm, _, err := compiler.Compile(string(arc.Data), arc.Filename, "", "", true)
 	if err != nil {
 		return nil, err
 	}
+	initctx := NewInitContext(goja.New(), compiler, new(context.Context), arc.FS, arc.Pwd)
 	initctx.files = arc.Files
 
 	env := arc.Env

js/initcontext.go

@@ -159,7 +159,7 @@ func (i *InitContext) requireFile(name string) (goja.Value, error) {
 }
 
 func (i *InitContext) compileImport(src, filename string) (*goja.Program, error) {
-	pgm, _, err := i.compiler.Compile(src, filename, "(function(){", "})()", true)
+	pgm, _, err := i.compiler.Compile(src, filename, "(function(){\n", "\n})()\n", true)
 	return pgm, err
 }
 

js/initcontext_test.go

@@ -128,7 +128,7 @@ func TestInitContextRequire(t *testing.T) {
 				Filename: "/script.js",
 				Data:     []byte(`import "/file.js"; export default function() {}`),
 			}, fs, lib.RuntimeOptions{})
-			assert.EqualError(t, err, "Error: aaaa at /file.js:1:19(4)")
+			assert.EqualError(t, err, "Error: aaaa at /file.js:2:7(4)")
 		})
 
 		imports := map[string]struct {

js/runner_test.go

@@ -203,7 +203,7 @@ func TestOptionsPropagationToScript(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, expScriptOptions, r1.GetOptions())
 
-	r2, err := NewFromArchive(r1.MakeArchive(), lib.RuntimeOptions{Env: map[string]string{"expectedSetupTimeout": "1s"}})
+	r2, err := NewFromArchive(r1.MakeArchive(), lib.RuntimeOptions{Env: map[string]string{"expectedSetupTimeout": "3s"}})
 
 	require.NoError(t, err)
 	require.Equal(t, expScriptOptions, r2.GetOptions())

release notes/upcoming.md

@@ -10,4 +10,4 @@ Description of feature.
 
 ## Bugs fixed!
 
-* Category: description of bug. (#PR)
+* JS: Fix a babel transformation issue that caused closing brackets to sometimes be commented out. (#853)