Includes rust_binary in rust-project.json

Until now, only rust_library (and their derivatives such as
rust_library_host) were reported in rust-project.json. Adds support for
rust_binary and rust_tests.

Bug: 174743191
Test: Validate auto-completion in keystore2_main.rs
Change-Id: I17b3ec29e233f29b7abd16dc771070ada48d17fb
diff --git a/rust/project_json.go b/rust/project_json.go
index 8d9e50c..c4d60ad 100644
--- a/rust/project_json.go
+++ b/rust/project_json.go
@@ -75,12 +75,16 @@
 	android.RegisterSingletonType("rust_project_generator", rustProjectGeneratorSingleton)
 }
 
-// librarySource finds the main source file (.rs) for a crate.
-func librarySource(ctx android.SingletonContext, rModule *Module, rustLib *libraryDecorator) (string, bool) {
-	srcs := rustLib.baseCompiler.Properties.Srcs
+// crateSource finds the main source file (.rs) for a crate.
+func crateSource(ctx android.SingletonContext, rModule *Module, comp *baseCompiler) (string, bool) {
+	srcs := comp.Properties.Srcs
 	if len(srcs) != 0 {
 		return path.Join(ctx.ModuleDir(rModule), srcs[0]), true
 	}
+	rustLib, ok := rModule.compiler.(*libraryDecorator)
+	if !ok {
+		return "", false
+	}
 	if !rustLib.source() {
 		return "", false
 	}
@@ -132,8 +136,15 @@
 	if rModule.compiler == nil {
 		return 0, "", false
 	}
-	rustLib, ok := rModule.compiler.(*libraryDecorator)
-	if !ok {
+	var comp *baseCompiler
+	switch c := rModule.compiler.(type) {
+	case *libraryDecorator:
+		comp = c.baseCompiler
+	case *binaryDecorator:
+		comp = c.baseCompiler
+	case *testDecorator:
+		comp = c.binaryDecorator.baseCompiler
+	default:
 		return 0, "", false
 	}
 	moduleName := ctx.ModuleName(module)
@@ -146,12 +157,12 @@
 		return cInfo.ID, crateName, true
 	}
 	crate := rustProjectCrate{Deps: make([]rustProjectDep, 0), Cfgs: make([]string, 0)}
-	rootModule, ok := librarySource(ctx, rModule, rustLib)
+	rootModule, ok := crateSource(ctx, rModule, comp)
 	if !ok {
 		return 0, "", false
 	}
 	crate.RootModule = rootModule
-	crate.Edition = rustLib.baseCompiler.edition()
+	crate.Edition = comp.edition()
 
 	deps := make(map[string]int)
 	singleton.mergeDependencies(ctx, module, &crate, deps)
diff --git a/rust/project_json_test.go b/rust/project_json_test.go
index 16699c1..aff1697 100644
--- a/rust/project_json_test.go
+++ b/rust/project_json_test.go
@@ -67,6 +67,37 @@
 	return crates
 }
 
+// validateCrate ensures that a crate can be parsed as a map.
+func validateCrate(t *testing.T, crate interface{}) map[string]interface{} {
+	c, ok := crate.(map[string]interface{})
+	if !ok {
+		t.Fatalf("Unexpected type for crate: %v", c)
+	}
+	return c
+}
+
+// validateDependencies parses the dependencies for a crate. It returns a list
+// of the dependencies name.
+func validateDependencies(t *testing.T, crate map[string]interface{}) []string {
+	var dependencies []string
+	deps, ok := crate["deps"].([]interface{})
+	if !ok {
+		t.Errorf("Unexpected format for deps: %v", crate["deps"])
+	}
+	for _, dep := range deps {
+		d, ok := dep.(map[string]interface{})
+		if !ok {
+			t.Errorf("Unexpected format for dependency: %v", dep)
+		}
+		name, ok := d["name"].(string)
+		if !ok {
+			t.Errorf("Dependency is missing the name key: %v", d)
+		}
+		dependencies = append(dependencies, name)
+	}
+	return dependencies
+}
+
 func TestProjectJsonDep(t *testing.T) {
 	bp := `
 	rust_library {
@@ -85,6 +116,29 @@
 	validateJsonCrates(t, jsonContent)
 }
 
+func TestProjectJsonBinary(t *testing.T) {
+	bp := `
+	rust_binary {
+		name: "liba",
+		srcs: ["a/src/lib.rs"],
+		crate_name: "a"
+	}
+	`
+	jsonContent := testProjectJson(t, bp)
+	crates := validateJsonCrates(t, jsonContent)
+	for _, c := range crates {
+		crate := validateCrate(t, c)
+		rootModule, ok := crate["root_module"].(string)
+		if !ok {
+			t.Fatalf("Unexpected type for root_module: %v", crate["root_module"])
+		}
+		if rootModule == "a/src/lib.rs" {
+			return
+		}
+	}
+	t.Errorf("Entry for binary %q not found: %s", "a", jsonContent)
+}
+
 func TestProjectJsonBindGen(t *testing.T) {
 	bp := `
 	rust_library {
@@ -116,10 +170,7 @@
 	jsonContent := testProjectJson(t, bp)
 	crates := validateJsonCrates(t, jsonContent)
 	for _, c := range crates {
-		crate, ok := c.(map[string]interface{})
-		if !ok {
-			t.Fatalf("Unexpected type for crate: %v", c)
-		}
+		crate := validateCrate(t, c)
 		rootModule, ok := crate["root_module"].(string)
 		if !ok {
 			t.Fatalf("Unexpected type for root_module: %v", crate["root_module"])
@@ -133,16 +184,8 @@
 		}
 		// Check that libbindings1 does not depend on itself.
 		if strings.Contains(rootModule, "libbindings1") {
-			deps, ok := crate["deps"].([]interface{})
-			if !ok {
-				t.Errorf("Unexpected format for deps: %v", crate["deps"])
-			}
-			for _, dep := range deps {
-				d, ok := dep.(map[string]interface{})
-				if !ok {
-					t.Errorf("Unexpected format for dep: %v", dep)
-				}
-				if d["name"] == "bindings1" {
+			for _, depName := range validateDependencies(t, crate) {
+				if depName == "bindings1" {
 					t.Errorf("libbindings1 depends on itself")
 				}
 			}
@@ -171,20 +214,18 @@
 	`
 	jsonContent := testProjectJson(t, bp)
 	crates := validateJsonCrates(t, jsonContent)
-	for _, crate := range crates {
-		c := crate.(map[string]interface{})
-		if c["root_module"] == "b/src/lib.rs" {
-			deps, ok := c["deps"].([]interface{})
-			if !ok {
-				t.Errorf("Unexpected format for deps: %v", c["deps"])
-			}
+	for _, c := range crates {
+		crate := validateCrate(t, c)
+		rootModule, ok := crate["root_module"].(string)
+		if !ok {
+			t.Fatalf("Unexpected type for root_module: %v", crate["root_module"])
+		}
+		// Make sure that b has 2 different dependencies.
+		if rootModule == "b/src/lib.rs" {
 			aCount := 0
-			for _, dep := range deps {
-				d, ok := dep.(map[string]interface{})
-				if !ok {
-					t.Errorf("Unexpected format for dep: %v", dep)
-				}
-				if d["name"] == "a" {
+			deps := validateDependencies(t, crate)
+			for _, depName := range deps {
+				if depName == "a" {
 					aCount++
 				}
 			}