diff --git a/bp2build/genrule_conversion_test.go b/bp2build/genrule_conversion_test.go
new file mode 100644
index 0000000..a991180
--- /dev/null
+++ b/bp2build/genrule_conversion_test.go
@@ -0,0 +1,479 @@
+// 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 bp2build
+
+import (
+	"android/soong/android"
+	"android/soong/genrule"
+	"strings"
+	"testing"
+)
+
+func TestGenruleBp2Build(t *testing.T) {
+	otherGenruleBp := map[string]string{
+		"other/Android.bp": `genrule {
+    name: "foo.tool",
+    out: ["foo_tool.out"],
+    srcs: ["foo_tool.in"],
+    cmd: "cp $(in) $(out)",
+}
+genrule {
+    name: "other.tool",
+    out: ["other_tool.out"],
+    srcs: ["other_tool.in"],
+    cmd: "cp $(in) $(out)",
+}`,
+	}
+
+	testCases := []bp2buildTestCase{
+		{
+			description:                        "genrule with command line variable replacements",
+			moduleTypeUnderTest:                "genrule",
+			moduleTypeUnderTestFactory:         genrule.GenRuleFactory,
+			moduleTypeUnderTestBp2BuildMutator: genrule.GenruleBp2Build,
+			blueprint: `genrule {
+    name: "foo.tool",
+    out: ["foo_tool.out"],
+    srcs: ["foo_tool.in"],
+    cmd: "cp $(in) $(out)",
+    bazel_module: { bp2build_available: true },
+}
+
+genrule {
+    name: "foo",
+    out: ["foo.out"],
+    srcs: ["foo.in"],
+    tools: [":foo.tool"],
+    cmd: "$(location :foo.tool) --genDir=$(genDir) arg $(in) $(out)",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{
+				`genrule(
+    name = "foo",
+    cmd = "$(location :foo.tool) --genDir=$(GENDIR) arg $(SRCS) $(OUTS)",
+    outs = ["foo.out"],
+    srcs = ["foo.in"],
+    tools = [":foo.tool"],
+)`,
+				`genrule(
+    name = "foo.tool",
+    cmd = "cp $(SRCS) $(OUTS)",
+    outs = ["foo_tool.out"],
+    srcs = ["foo_tool.in"],
+)`,
+			},
+		},
+		{
+			description:                        "genrule using $(locations :label)",
+			moduleTypeUnderTest:                "genrule",
+			moduleTypeUnderTestFactory:         genrule.GenRuleFactory,
+			moduleTypeUnderTestBp2BuildMutator: genrule.GenruleBp2Build,
+			blueprint: `genrule {
+    name: "foo.tools",
+    out: ["foo_tool.out", "foo_tool2.out"],
+    srcs: ["foo_tool.in"],
+    cmd: "cp $(in) $(out)",
+    bazel_module: { bp2build_available: true },
+}
+
+genrule {
+    name: "foo",
+    out: ["foo.out"],
+    srcs: ["foo.in"],
+    tools: [":foo.tools"],
+    cmd: "$(locations :foo.tools) -s $(out) $(in)",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{`genrule(
+    name = "foo",
+    cmd = "$(locations :foo.tools) -s $(OUTS) $(SRCS)",
+    outs = ["foo.out"],
+    srcs = ["foo.in"],
+    tools = [":foo.tools"],
+)`,
+				`genrule(
+    name = "foo.tools",
+    cmd = "cp $(SRCS) $(OUTS)",
+    outs = [
+        "foo_tool.out",
+        "foo_tool2.out",
+    ],
+    srcs = ["foo_tool.in"],
+)`,
+			},
+		},
+		{
+			description:                        "genrule using $(locations //absolute:label)",
+			moduleTypeUnderTest:                "genrule",
+			moduleTypeUnderTestFactory:         genrule.GenRuleFactory,
+			moduleTypeUnderTestBp2BuildMutator: genrule.GenruleBp2Build,
+			blueprint: `genrule {
+    name: "foo",
+    out: ["foo.out"],
+    srcs: ["foo.in"],
+    tool_files: [":foo.tool"],
+    cmd: "$(locations :foo.tool) -s $(out) $(in)",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{`genrule(
+    name = "foo",
+    cmd = "$(locations //other:foo.tool) -s $(OUTS) $(SRCS)",
+    outs = ["foo.out"],
+    srcs = ["foo.in"],
+    tools = ["//other:foo.tool"],
+)`,
+			},
+			filesystem: otherGenruleBp,
+		},
+		{
+			description:                        "genrule srcs using $(locations //absolute:label)",
+			moduleTypeUnderTest:                "genrule",
+			moduleTypeUnderTestFactory:         genrule.GenRuleFactory,
+			moduleTypeUnderTestBp2BuildMutator: genrule.GenruleBp2Build,
+			blueprint: `genrule {
+    name: "foo",
+    out: ["foo.out"],
+    srcs: [":other.tool"],
+    tool_files: [":foo.tool"],
+    cmd: "$(locations :foo.tool) -s $(out) $(location :other.tool)",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{`genrule(
+    name = "foo",
+    cmd = "$(locations //other:foo.tool) -s $(OUTS) $(location //other:other.tool)",
+    outs = ["foo.out"],
+    srcs = ["//other:other.tool"],
+    tools = ["//other:foo.tool"],
+)`,
+			},
+			filesystem: otherGenruleBp,
+		},
+		{
+			description:                        "genrule using $(location) label should substitute first tool label automatically",
+			moduleTypeUnderTest:                "genrule",
+			moduleTypeUnderTestFactory:         genrule.GenRuleFactory,
+			moduleTypeUnderTestBp2BuildMutator: genrule.GenruleBp2Build,
+			blueprint: `genrule {
+    name: "foo",
+    out: ["foo.out"],
+    srcs: ["foo.in"],
+    tool_files: [":foo.tool", ":other.tool"],
+    cmd: "$(location) -s $(out) $(in)",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{`genrule(
+    name = "foo",
+    cmd = "$(location //other:foo.tool) -s $(OUTS) $(SRCS)",
+    outs = ["foo.out"],
+    srcs = ["foo.in"],
+    tools = [
+        "//other:foo.tool",
+        "//other:other.tool",
+    ],
+)`,
+			},
+			filesystem: otherGenruleBp,
+		},
+		{
+			description:                        "genrule using $(locations) label should substitute first tool label automatically",
+			moduleTypeUnderTest:                "genrule",
+			moduleTypeUnderTestFactory:         genrule.GenRuleFactory,
+			moduleTypeUnderTestBp2BuildMutator: genrule.GenruleBp2Build,
+			blueprint: `genrule {
+    name: "foo",
+    out: ["foo.out"],
+    srcs: ["foo.in"],
+    tools: [":foo.tool", ":other.tool"],
+    cmd: "$(locations) -s $(out) $(in)",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{`genrule(
+    name = "foo",
+    cmd = "$(locations //other:foo.tool) -s $(OUTS) $(SRCS)",
+    outs = ["foo.out"],
+    srcs = ["foo.in"],
+    tools = [
+        "//other:foo.tool",
+        "//other:other.tool",
+    ],
+)`,
+			},
+			filesystem: otherGenruleBp,
+		},
+		{
+			description:                        "genrule without tools or tool_files can convert successfully",
+			moduleTypeUnderTest:                "genrule",
+			moduleTypeUnderTestFactory:         genrule.GenRuleFactory,
+			moduleTypeUnderTestBp2BuildMutator: genrule.GenruleBp2Build,
+			blueprint: `genrule {
+    name: "foo",
+    out: ["foo.out"],
+    srcs: ["foo.in"],
+    cmd: "cp $(in) $(out)",
+    bazel_module: { bp2build_available: true },
+}`,
+			expectedBazelTargets: []string{`genrule(
+    name = "foo",
+    cmd = "cp $(SRCS) $(OUTS)",
+    outs = ["foo.out"],
+    srcs = ["foo.in"],
+)`,
+			},
+		},
+	}
+
+	dir := "."
+	for _, testCase := range testCases {
+		fs := make(map[string][]byte)
+		toParse := []string{
+			"Android.bp",
+		}
+		for f, content := range testCase.filesystem {
+			if strings.HasSuffix(f, "Android.bp") {
+				toParse = append(toParse, f)
+			}
+			fs[f] = []byte(content)
+		}
+		config := android.TestConfig(buildDir, nil, testCase.blueprint, fs)
+		ctx := android.NewTestContext(config)
+		ctx.RegisterModuleType(testCase.moduleTypeUnderTest, testCase.moduleTypeUnderTestFactory)
+		ctx.RegisterBp2BuildMutator(testCase.moduleTypeUnderTest, testCase.moduleTypeUnderTestBp2BuildMutator)
+		ctx.RegisterForBazelConversion()
+
+		_, errs := ctx.ParseFileList(dir, toParse)
+		if errored(t, testCase, errs) {
+			continue
+		}
+		_, errs = ctx.ResolveDependencies(config)
+		if errored(t, testCase, errs) {
+			continue
+		}
+
+		checkDir := dir
+		if testCase.dir != "" {
+			checkDir = testCase.dir
+		}
+
+		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
+		bazelTargets := generateBazelTargetsForDir(codegenCtx, checkDir)
+		if actualCount, expectedCount := len(bazelTargets), len(testCase.expectedBazelTargets); actualCount != expectedCount {
+			t.Errorf("%s: Expected %d bazel target, got %d", testCase.description, expectedCount, actualCount)
+		} else {
+			for i, target := range bazelTargets {
+				if w, g := testCase.expectedBazelTargets[i], target.content; w != g {
+					t.Errorf(
+						"%s: Expected generated Bazel target to be '%s', got '%s'",
+						testCase.description,
+						w,
+						g,
+					)
+				}
+			}
+		}
+	}
+}
+
+func TestBp2BuildInlinesDefaults(t *testing.T) {
+	testCases := []struct {
+		moduleTypesUnderTest      map[string]android.ModuleFactory
+		bp2buildMutatorsUnderTest map[string]bp2buildMutator
+		bp                        string
+		expectedBazelTarget       string
+		description               string
+	}{
+		{
+			moduleTypesUnderTest: map[string]android.ModuleFactory{
+				"genrule":          genrule.GenRuleFactory,
+				"genrule_defaults": func() android.Module { return genrule.DefaultsFactory() },
+			},
+			bp2buildMutatorsUnderTest: map[string]bp2buildMutator{
+				"genrule": genrule.GenruleBp2Build,
+			},
+			bp: `genrule_defaults {
+    name: "gen_defaults",
+    cmd: "do-something $(in) $(out)",
+}
+genrule {
+    name: "gen",
+    out: ["out"],
+    srcs: ["in1"],
+    defaults: ["gen_defaults"],
+    bazel_module: { bp2build_available: true },
+}
+`,
+			expectedBazelTarget: `genrule(
+    name = "gen",
+    cmd = "do-something $(SRCS) $(OUTS)",
+    outs = ["out"],
+    srcs = ["in1"],
+)`,
+			description: "genrule applies properties from a genrule_defaults dependency if not specified",
+		},
+		{
+			moduleTypesUnderTest: map[string]android.ModuleFactory{
+				"genrule":          genrule.GenRuleFactory,
+				"genrule_defaults": func() android.Module { return genrule.DefaultsFactory() },
+			},
+			bp2buildMutatorsUnderTest: map[string]bp2buildMutator{
+				"genrule": genrule.GenruleBp2Build,
+			},
+			bp: `genrule_defaults {
+    name: "gen_defaults",
+    out: ["out-from-defaults"],
+    srcs: ["in-from-defaults"],
+    cmd: "cmd-from-defaults",
+}
+genrule {
+    name: "gen",
+    out: ["out"],
+    srcs: ["in1"],
+    defaults: ["gen_defaults"],
+    cmd: "do-something $(in) $(out)",
+    bazel_module: { bp2build_available: true },
+}
+`,
+			expectedBazelTarget: `genrule(
+    name = "gen",
+    cmd = "do-something $(SRCS) $(OUTS)",
+    outs = [
+        "out-from-defaults",
+        "out",
+    ],
+    srcs = [
+        "in-from-defaults",
+        "in1",
+    ],
+)`,
+			description: "genrule does merges properties from a genrule_defaults dependency, latest-first",
+		},
+		{
+			moduleTypesUnderTest: map[string]android.ModuleFactory{
+				"genrule":          genrule.GenRuleFactory,
+				"genrule_defaults": func() android.Module { return genrule.DefaultsFactory() },
+			},
+			bp2buildMutatorsUnderTest: map[string]bp2buildMutator{
+				"genrule": genrule.GenruleBp2Build,
+			},
+			bp: `genrule_defaults {
+    name: "gen_defaults1",
+    cmd: "cp $(in) $(out)",
+}
+
+genrule_defaults {
+    name: "gen_defaults2",
+    srcs: ["in1"],
+}
+
+genrule {
+    name: "gen",
+    out: ["out"],
+    defaults: ["gen_defaults1", "gen_defaults2"],
+    bazel_module: { bp2build_available: true },
+}
+`,
+			expectedBazelTarget: `genrule(
+    name = "gen",
+    cmd = "cp $(SRCS) $(OUTS)",
+    outs = ["out"],
+    srcs = ["in1"],
+)`,
+			description: "genrule applies properties from list of genrule_defaults",
+		},
+		{
+			moduleTypesUnderTest: map[string]android.ModuleFactory{
+				"genrule":          genrule.GenRuleFactory,
+				"genrule_defaults": func() android.Module { return genrule.DefaultsFactory() },
+			},
+			bp2buildMutatorsUnderTest: map[string]bp2buildMutator{
+				"genrule": genrule.GenruleBp2Build,
+			},
+			bp: `genrule_defaults {
+    name: "gen_defaults1",
+    defaults: ["gen_defaults2"],
+    cmd: "cmd1 $(in) $(out)", // overrides gen_defaults2's cmd property value.
+}
+
+genrule_defaults {
+    name: "gen_defaults2",
+    defaults: ["gen_defaults3"],
+    cmd: "cmd2 $(in) $(out)",
+    out: ["out-from-2"],
+    srcs: ["in1"],
+}
+
+genrule_defaults {
+    name: "gen_defaults3",
+    out: ["out-from-3"],
+    srcs: ["srcs-from-3"],
+}
+
+genrule {
+    name: "gen",
+    out: ["out"],
+    defaults: ["gen_defaults1"],
+    bazel_module: { bp2build_available: true },
+}
+`,
+			expectedBazelTarget: `genrule(
+    name = "gen",
+    cmd = "cmd1 $(SRCS) $(OUTS)",
+    outs = [
+        "out-from-3",
+        "out-from-2",
+        "out",
+    ],
+    srcs = [
+        "srcs-from-3",
+        "in1",
+    ],
+)`,
+			description: "genrule applies properties from genrule_defaults transitively",
+		},
+	}
+
+	dir := "."
+	for _, testCase := range testCases {
+		config := android.TestConfig(buildDir, nil, testCase.bp, nil)
+		ctx := android.NewTestContext(config)
+		for m, factory := range testCase.moduleTypesUnderTest {
+			ctx.RegisterModuleType(m, factory)
+		}
+		for mutator, f := range testCase.bp2buildMutatorsUnderTest {
+			ctx.RegisterBp2BuildMutator(mutator, f)
+		}
+		ctx.RegisterForBazelConversion()
+
+		_, errs := ctx.ParseFileList(dir, []string{"Android.bp"})
+		android.FailIfErrored(t, errs)
+		_, errs = ctx.ResolveDependencies(config)
+		android.FailIfErrored(t, errs)
+
+		codegenCtx := NewCodegenContext(config, *ctx.Context, Bp2Build)
+		bazelTargets := generateBazelTargetsForDir(codegenCtx, dir)
+		if actualCount := len(bazelTargets); actualCount != 1 {
+			t.Fatalf("%s: Expected 1 bazel target, got %d", testCase.description, actualCount)
+		}
+
+		actualBazelTarget := bazelTargets[0]
+		if actualBazelTarget.content != testCase.expectedBazelTarget {
+			t.Errorf(
+				"%s: Expected generated Bazel target to be '%s', got '%s'",
+				testCase.description,
+				testCase.expectedBazelTarget,
+				actualBazelTarget.content,
+			)
+		}
+	}
+}