diff --git a/java/droiddoc_test.go b/java/droiddoc_test.go
new file mode 100644
index 0000000..2b324ae
--- /dev/null
+++ b/java/droiddoc_test.go
@@ -0,0 +1,147 @@
+// Copyright 2021 Google Inc. 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 java
+
+import (
+	"reflect"
+	"strings"
+	"testing"
+
+	"android/soong/android"
+)
+
+func TestDroiddoc(t *testing.T) {
+	ctx, _ := testJavaWithFS(t, `
+		droiddoc_exported_dir {
+		    name: "droiddoc-templates-sdk",
+		    path: ".",
+		}
+		filegroup {
+		    name: "bar-doc-aidl-srcs",
+		    srcs: ["bar-doc/IBar.aidl"],
+		    path: "bar-doc",
+		}
+		droidstubs {
+		    name: "bar-stubs",
+		    srcs: [
+		        "bar-doc/a.java",
+		    ],
+		    exclude_srcs: [
+		        "bar-doc/b.java"
+		    ],
+		    api_levels_annotations_dirs: [
+		      "droiddoc-templates-sdk",
+		    ],
+		    api_levels_annotations_enabled: true,
+		}
+		droiddoc {
+		    name: "bar-doc",
+		    srcs: [
+		        ":bar-stubs",
+		        "bar-doc/IFoo.aidl",
+		        ":bar-doc-aidl-srcs",
+		    ],
+		    custom_template: "droiddoc-templates-sdk",
+		    hdf: [
+		        "android.whichdoc offline",
+		    ],
+		    knowntags: [
+		        "bar-doc/known_oj_tags.txt",
+		    ],
+		    proofread_file: "libcore-proofread.txt",
+		    todo_file: "libcore-docs-todo.html",
+		    flags: ["-offlinemode -title \"libcore\""],
+		}
+		`,
+		map[string][]byte{
+			"bar-doc/a.java": nil,
+			"bar-doc/b.java": nil,
+		})
+	barStubs := ctx.ModuleForTests("bar-stubs", "android_common")
+	barStubsOutputs, err := barStubs.Module().(*Droidstubs).OutputFiles("")
+	if err != nil {
+		t.Errorf("Unexpected error %q retrieving \"bar-stubs\" output file", err)
+	}
+	if len(barStubsOutputs) != 1 {
+		t.Errorf("Expected one output from \"bar-stubs\" got %s", barStubsOutputs)
+	}
+
+	barStubsOutput := barStubsOutputs[0]
+	barDoc := ctx.ModuleForTests("bar-doc", "android_common")
+	javaDoc := barDoc.Rule("javadoc").RelativeToTop()
+	if g, w := android.PathsRelativeToTop(javaDoc.Implicits), android.PathRelativeToTop(barStubsOutput); !inList(w, g) {
+		t.Errorf("implicits of bar-doc must contain %q, but was %q.", w, g)
+	}
+
+	expected := "-sourcepath out/soong/.intermediates/bar-doc/android_common/srcjars "
+	if !strings.Contains(javaDoc.RuleParams.Command, expected) {
+		t.Errorf("bar-doc command does not contain flag %q, but should\n%q", expected, javaDoc.RuleParams.Command)
+	}
+
+	aidl := barDoc.Rule("aidl")
+	if g, w := android.PathsRelativeToTop(javaDoc.Implicits), android.PathRelativeToTop(aidl.Output); !inList(w, g) {
+		t.Errorf("implicits of bar-doc must contain %q, but was %q.", w, g)
+	}
+
+	if g, w := aidl.Implicits.Strings(), []string{"bar-doc/IBar.aidl", "bar-doc/IFoo.aidl"}; !reflect.DeepEqual(w, g) {
+		t.Errorf("aidl inputs must be %q, but was %q", w, g)
+	}
+}
+
+func TestDroiddocArgsAndFlagsCausesError(t *testing.T) {
+	testJavaError(t, "flags is set. Cannot set args", `
+		droiddoc_exported_dir {
+		    name: "droiddoc-templates-sdk",
+		    path: ".",
+		}
+		filegroup {
+		    name: "bar-doc-aidl-srcs",
+		    srcs: ["bar-doc/IBar.aidl"],
+		    path: "bar-doc",
+		}
+		droidstubs {
+		    name: "bar-stubs",
+		    srcs: [
+		        "bar-doc/a.java",
+		    ],
+		    exclude_srcs: [
+		        "bar-doc/b.java"
+		    ],
+		    api_levels_annotations_dirs: [
+		      "droiddoc-templates-sdk",
+		    ],
+		    api_levels_annotations_enabled: true,
+		}
+		droiddoc {
+		    name: "bar-doc",
+		    srcs: [
+		        ":bar-stubs",
+		        "bar-doc/IFoo.aidl",
+		        ":bar-doc-aidl-srcs",
+		    ],
+		    custom_template: "droiddoc-templates-sdk",
+		    hdf: [
+		        "android.whichdoc offline",
+		    ],
+		    knowntags: [
+		        "bar-doc/known_oj_tags.txt",
+		    ],
+		    proofread_file: "libcore-proofread.txt",
+		    todo_file: "libcore-docs-todo.html",
+		    flags: ["-offlinemode -title \"libcore\""],
+		    args: "-offlinemode -title \"libcore\"",
+		}
+		`)
+}