Make js.Build fully support modules

Fixes #7816
Fixes #7777
Fixes #7916

resources/jsconfig/jsconfig_test.go

@@ -0,0 +1,35 @@
+// Copyright 2020 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package jsconfig
+
+import (
+	"path/filepath"
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+)
+
+func TestJsConfigBuilder(t *testing.T) {
+	c := qt.New(t)
+
+	b := NewBuilder()
+	b.AddSourceRoot("/c/assets")
+	b.AddSourceRoot("/d/assets")
+
+	conf := b.Build("/a/b")
+	c.Assert(conf.CompilerOptions.BaseURL, qt.Equals, ".")
+	c.Assert(conf.CompilerOptions.Paths["*"], qt.DeepEquals, []string{filepath.FromSlash("../../c/assets/*"), filepath.FromSlash("../../d/assets/*")})
+
+	c.Assert(NewBuilder().Build("/a/b"), qt.IsNil)
+}