diff --git a/rust/project_json.go b/rust/project_json.go
index 75375408c..41dd194ee 100644
--- a/rust/project_json.go
+++ b/rust/project_json.go
@@ -75,6 +75,7 @@ func mergeDependencies(ctx android.SingletonContext, project *rustProjectJson,
 	knownCrates map[string]crateInfo, module android.Module,
 	crate *rustProjectCrate, deps map[string]int) {
 
+	//TODO(tweek): The stdlib dependencies do not appear here. We need to manually add them.
 	ctx.VisitDirectDeps(module, func(child android.Module) {
 		childId, childName, ok := appendLibraryAndDeps(ctx, project, knownCrates, child)
 		if !ok {
@@ -114,11 +115,8 @@ func appendLibraryAndDeps(ctx android.SingletonContext, project *rustProjectJson
 		return cInfo.ID, crateName, true
 	}
 	crate := rustProjectCrate{Deps: make([]rustProjectDep, 0), Cfgs: make([]string, 0)}
-	srcs := rustLib.baseCompiler.Properties.Srcs
-	if len(srcs) == 0 {
-		return 0, "", false
-	}
-	crate.RootModule = path.Join(ctx.ModuleDir(rModule), srcs[0])
+	src := rustLib.baseCompiler.Properties.Srcs[0]
+	crate.RootModule = path.Join(ctx.ModuleDir(rModule), src)
 	crate.Edition = rustLib.baseCompiler.edition()
 
 	deps := make(map[string]int)
diff --git a/rust/project_json_test.go b/rust/project_json_test.go
index 89ba8d352..6786e72c7 100644
--- a/rust/project_json_test.go
+++ b/rust/project_json_test.go
@@ -15,7 +15,6 @@
 package rust
 
 import (
-	"encoding/json"
 	"io/ioutil"
 	"path/filepath"
 	"testing"
@@ -24,12 +23,20 @@ import (
 	"android/soong/cc"
 )
 
-// testProjectJson run the generation of rust-project.json. It returns the raw
-// content of the generated file.
-func testProjectJson(t *testing.T, bp string, fs map[string][]byte) []byte {
+func TestProjectJson(t *testing.T) {
+	bp := `rust_library {
+		  name: "liba",
+		  srcs: ["src/lib.rs"],
+		  crate_name: "a"
+		}` + GatherRequiredDepsForTest()
+	env := map[string]string{"SOONG_GEN_RUST_PROJECT": "1"}
+	fs := map[string][]byte{
+		"foo.rs":     nil,
+		"src/lib.rs": nil,
+	}
+
 	cc.GatherRequiredFilesForTest(fs)
 
-	env := map[string]string{"SOONG_GEN_RUST_PROJECT": "1"}
 	config := android.TestArchConfig(buildDir, env, bp, fs)
 	ctx := CreateTestContext()
 	ctx.Register(config)
@@ -41,79 +48,8 @@ func testProjectJson(t *testing.T, bp string, fs map[string][]byte) []byte {
 	// The JSON file is generated via WriteFileToOutputDir. Therefore, it
 	// won't appear in the Output of the TestingSingleton. Manually verify
 	// it exists.
-	content, err := ioutil.ReadFile(filepath.Join(buildDir, rustProjectJsonFileName))
+	_, err := ioutil.ReadFile(filepath.Join(buildDir, "rust-project.json"))
 	if err != nil {
 		t.Errorf("rust-project.json has not been generated")
 	}
-	return content
-}
-
-// validateJsonCrates validates that content follows the basic structure of
-// rust-project.json. It returns the crates attribute if the validation
-// succeeded.
-// It uses an empty interface instead of relying on a defined structure to
-// avoid a strong dependency on our implementation.
-func validateJsonCrates(t *testing.T, rawContent []byte) []interface{} {
-	var content interface{}
-	err := json.Unmarshal(rawContent, &content)
-	if err != nil {
-		t.Errorf("Unable to parse the rust-project.json as JSON: %v", err)
-	}
-	root, ok := content.(map[string]interface{})
-	if !ok {
-		t.Errorf("Unexpected JSON format: %v", content)
-	}
-	if _, ok = root["crates"]; !ok {
-		t.Errorf("No crates attribute in rust-project.json: %v", root)
-	}
-	crates, ok := root["crates"].([]interface{})
-	if !ok {
-		t.Errorf("Unexpected crates format: %v", root["crates"])
-	}
-	return crates
-}
-
-func TestProjectJsonDep(t *testing.T) {
-	bp := `
-	rust_library {
-		name: "liba",
-		srcs: ["a/src/lib.rs"],
-		crate_name: "a"
-	}
-	rust_library {
-		name: "libb",
-		srcs: ["b/src/lib.rs"],
-		crate_name: "b",
-		rlibs: ["liba"],
-	}
-	` + GatherRequiredDepsForTest()
-	fs := map[string][]byte{
-		"a/src/lib.rs": nil,
-		"b/src/lib.rs": nil,
-	}
-	jsonContent := testProjectJson(t, bp, fs)
-	validateJsonCrates(t, jsonContent)
-}
-
-func TestProjectJsonBindGen(t *testing.T) {
-	bp := `
-	rust_library {
-		name: "liba",
-		srcs: ["src/lib.rs"],
-		rlibs: ["libbindings"],
-		crate_name: "a"
-	}
-	rust_bindgen {
-		name: "libbindings",
-		crate_name: "bindings",
-		source_stem: "bindings",
-		host_supported: true,
-		wrapper_src: "src/any.h",
-	}
-	` + GatherRequiredDepsForTest()
-	fs := map[string][]byte{
-		"src/lib.rs": nil,
-	}
-	jsonContent := testProjectJson(t, bp, fs)
-	validateJsonCrates(t, jsonContent)
 }