Split droidstubs out of droiddoc.go

Split part of droiddoc.go into droidstubs.go.  Also split droiddoc_test.go
and droidstubs_test.go out of java_test.go.

Test: go test ./java
Change-Id: Iea742e75b6925b135016f7bbf3a168c696a6c433
diff --git a/java/droidstubs_test.go b/java/droidstubs_test.go
new file mode 100644
index 0000000..d450c1a
--- /dev/null
+++ b/java/droidstubs_test.go
@@ -0,0 +1,138 @@
+// 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 (
+	"strings"
+	"testing"
+
+	"android/soong/android"
+)
+
+func TestDroidstubs(t *testing.T) {
+	ctx, _ := testJavaWithFS(t, `
+		droiddoc_exported_dir {
+			name: "droiddoc-templates-sdk",
+			path: ".",
+		}
+
+		droidstubs {
+			name: "bar-stubs",
+			srcs: ["bar-doc/a.java"],
+			api_levels_annotations_dirs: ["droiddoc-templates-sdk"],
+			api_levels_annotations_enabled: true,
+		}
+
+		droidstubs {
+			name: "bar-stubs-other",
+			srcs: ["bar-doc/a.java"],
+			high_mem: true,
+			api_levels_annotations_dirs: ["droiddoc-templates-sdk"],
+			api_levels_annotations_enabled: true,
+			api_levels_jar_filename: "android.other.jar",
+		}
+		`,
+		map[string][]byte{
+			"bar-doc/a.java": nil,
+		})
+	testcases := []struct {
+		moduleName          string
+		expectedJarFilename string
+		high_mem            bool
+	}{
+		{
+			moduleName:          "bar-stubs",
+			expectedJarFilename: "android.jar",
+			high_mem:            false,
+		},
+		{
+			moduleName:          "bar-stubs-other",
+			expectedJarFilename: "android.other.jar",
+			high_mem:            true,
+		},
+	}
+	for _, c := range testcases {
+		m := ctx.ModuleForTests(c.moduleName, "android_common")
+		metalava := m.Rule("metalava")
+		rp := metalava.RuleParams
+		expected := "--android-jar-pattern ./%/public/" + c.expectedJarFilename
+		if actual := rp.Command; !strings.Contains(actual, expected) {
+			t.Errorf("For %q, expected metalava argument %q, but was not found %q", c.moduleName, expected, actual)
+		}
+
+		if actual := rp.Pool != nil && strings.Contains(rp.Pool.String(), "highmem"); actual != c.high_mem {
+			t.Errorf("Expected %q high_mem to be %v, was %v", c.moduleName, c.high_mem, actual)
+		}
+	}
+}
+
+func TestDroidstubsWithSystemModules(t *testing.T) {
+	ctx, _ := testJava(t, `
+		droidstubs {
+		    name: "stubs-source-system-modules",
+		    srcs: [
+		        "bar-doc/a.java",
+		    ],
+				sdk_version: "none",
+				system_modules: "source-system-modules",
+		}
+
+		java_library {
+				name: "source-jar",
+		    srcs: [
+		        "a.java",
+		    ],
+		}
+
+		java_system_modules {
+				name: "source-system-modules",
+				libs: ["source-jar"],
+		}
+
+		droidstubs {
+		    name: "stubs-prebuilt-system-modules",
+		    srcs: [
+		        "bar-doc/a.java",
+		    ],
+				sdk_version: "none",
+				system_modules: "prebuilt-system-modules",
+		}
+
+		java_import {
+				name: "prebuilt-jar",
+				jars: ["a.jar"],
+		}
+
+		java_system_modules_import {
+				name: "prebuilt-system-modules",
+				libs: ["prebuilt-jar"],
+		}
+		`)
+
+	checkSystemModulesUseByDroidstubs(t, ctx, "stubs-source-system-modules", "source-jar.jar")
+
+	checkSystemModulesUseByDroidstubs(t, ctx, "stubs-prebuilt-system-modules", "prebuilt-jar.jar")
+}
+
+func checkSystemModulesUseByDroidstubs(t *testing.T, ctx *android.TestContext, moduleName string, systemJar string) {
+	metalavaRule := ctx.ModuleForTests(moduleName, "android_common").Rule("metalava")
+	var systemJars []string
+	for _, i := range metalavaRule.Implicits {
+		systemJars = append(systemJars, i.Base())
+	}
+	if len(systemJars) < 1 || systemJars[0] != systemJar {
+		t.Errorf("inputs of %q must be []string{%q}, but was %#v.", moduleName, systemJar, systemJars)
+	}
+}