diff --git a/android/all_teams_test.go b/android/all_teams_test.go
new file mode 100644
index 0000000..a02b86e
--- /dev/null
+++ b/android/all_teams_test.go
@@ -0,0 +1,208 @@
+// Copyright 2024 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 android
+
+import (
+	"android/soong/android/team_proto"
+	"log"
+	"testing"
+
+	"google.golang.org/protobuf/proto"
+)
+
+func TestAllTeams(t *testing.T) {
+	t.Parallel()
+	ctx := GroupFixturePreparers(
+		PrepareForTestWithTeamBuildComponents,
+		FixtureRegisterWithContext(func(ctx RegistrationContext) {
+			ctx.RegisterModuleType("fake", fakeModuleFactory)
+			ctx.RegisterParallelSingletonType("all_teams", AllTeamsFactory)
+		}),
+	).RunTestWithBp(t, `
+		fake {
+			name: "main_test",
+			team: "someteam",
+		}
+		team {
+			name: "someteam",
+			trendy_team_id: "cool_team",
+		}
+
+		team {
+			name: "team2",
+			trendy_team_id: "22222",
+		}
+
+		fake {
+			name: "tool",
+			team: "team2",
+		}
+
+		fake {
+			name: "noteam",
+		}
+	`)
+
+	var teams *team_proto.AllTeams
+	teams = getTeamProtoOutput(t, ctx)
+
+	// map of module name -> trendy team name.
+	actualTeams := make(map[string]*string)
+	for _, teamProto := range teams.Teams {
+		actualTeams[teamProto.GetTargetName()] = teamProto.TrendyTeamId
+	}
+	expectedTeams := map[string]*string{
+		"main_test": proto.String("cool_team"),
+		"tool":      proto.String("22222"),
+		"noteam":    nil,
+	}
+
+	AssertDeepEquals(t, "compare maps", expectedTeams, actualTeams)
+}
+
+func getTeamProtoOutput(t *testing.T, ctx *TestResult) *team_proto.AllTeams {
+	teams := new(team_proto.AllTeams)
+	config := ctx.SingletonForTests("all_teams")
+	allOutputs := config.AllOutputs()
+
+	protoPath := allOutputs[0]
+
+	out := config.MaybeOutput(protoPath)
+	outProto := []byte(ContentFromFileRuleForTests(t, ctx.TestContext, out))
+	if err := proto.Unmarshal(outProto, teams); err != nil {
+		log.Fatalln("Failed to parse teams proto:", err)
+	}
+	return teams
+}
+
+// Android.bp
+//
+//	team: team_top
+//
+// # dir1 has no modules with teams,
+// # but has a dir with no Android.bp
+// dir1/Android.bp
+//
+//	module_dir1
+//
+// # dirs without and Android.bp should be fine.
+// dir1/dir2/dir3/Android.bp
+//
+//	package {}
+//	module_dir123
+//
+// teams_dir/Android.bp
+//
+//	module_with_team1: team1
+//	team1: 111
+//
+// # team comes from upper package default
+// teams_dir/deeper/Android.bp
+//
+//	module2_with_team1: team1
+//
+// package_defaults/Android.bp
+// package_defaults/pd2/Android.bp
+//
+//	package{ default_team: team_top}
+//	module_pd2   ## should get team_top
+//
+// package_defaults/pd2/pd3/Android.bp
+//
+//	module_pd3  ## should get team_top
+func TestPackageLookup(t *testing.T) {
+	t.Parallel()
+	rootBp := `
+		team {
+			name: "team_top",
+			trendy_team_id: "trendy://team_top",
+		} `
+
+	dir1Bp := `
+		fake {
+			name: "module_dir1",
+		} `
+	dir3Bp := `
+                package {}
+		fake {
+			name: "module_dir123",
+		} `
+	teamsDirBp := `
+		fake {
+			name: "module_with_team1",
+                        team: "team1"
+
+		}
+		team {
+			name: "team1",
+			trendy_team_id: "111",
+		} `
+	teamsDirDeeper := `
+		fake {
+			name: "module2_with_team1",
+                        team: "team1"
+		} `
+	// create an empty one.
+	packageDefaultsBp := ""
+	packageDefaultspd2 := `
+                package { default_team: "team_top"}
+		fake {
+			name: "modulepd2",
+		} `
+
+	packageDefaultspd3 := `
+		fake {
+			name: "modulepd3",
+		}
+		fake {
+			name: "modulepd3b",
+			team: "team1"
+		} `
+
+	ctx := GroupFixturePreparers(
+		PrepareForTestWithTeamBuildComponents,
+		PrepareForTestWithPackageModule,
+		FixtureRegisterWithContext(func(ctx RegistrationContext) {
+			ctx.RegisterModuleType("fake", fakeModuleFactory)
+			ctx.RegisterParallelSingletonType("all_teams", AllTeamsFactory)
+		}),
+		FixtureAddTextFile("Android.bp", rootBp),
+		FixtureAddTextFile("dir1/Android.bp", dir1Bp),
+		FixtureAddTextFile("dir1/dir2/dir3/Android.bp", dir3Bp),
+		FixtureAddTextFile("teams_dir/Android.bp", teamsDirBp),
+		FixtureAddTextFile("teams_dir/deeper/Android.bp", teamsDirDeeper),
+		FixtureAddTextFile("package_defaults/Android.bp", packageDefaultsBp),
+		FixtureAddTextFile("package_defaults/pd2/Android.bp", packageDefaultspd2),
+		FixtureAddTextFile("package_defaults/pd2/pd3/Android.bp", packageDefaultspd3),
+	).RunTest(t)
+
+	var teams *team_proto.AllTeams
+	teams = getTeamProtoOutput(t, ctx)
+
+	// map of module name -> trendy team name.
+	actualTeams := make(map[string]*string)
+	for _, teamProto := range teams.Teams {
+		actualTeams[teamProto.GetTargetName()] = teamProto.TrendyTeamId
+	}
+	expectedTeams := map[string]*string{
+		"module_with_team1":  proto.String("111"),
+		"module2_with_team1": proto.String("111"),
+		"modulepd2":          proto.String("trendy://team_top"),
+		"modulepd3":          proto.String("trendy://team_top"),
+		"modulepd3b":         proto.String("111"),
+		"module_dir1":        nil,
+		"module_dir123":      nil,
+	}
+	AssertDeepEquals(t, "compare maps", expectedTeams, actualTeams)
+}