Update java templates in rbeconfigsgen.go (#999)

* Update java templates in rbeconfigsgen.go

Use @rules_java for bazel > 7.0.0

* Fix buildifier CI failures

Author: hvadehra

pkg/rbeconfigsgen/rbeconfigsgen.go

@@ -99,12 +99,33 @@ java_runtime(
     srcs = [],
     java_home = "{{ .JavaHome }}",
 )
+`))
+
+	// javaBuildTemplateLt7 is the Java toolchain config BUILD file template for Bazel versions
+	// >=5.0.0 (tentative?) and < 7.0.0.
+	javaBuildTemplateLt7 = template.Must(template.New("javaBuild").Parse(buildHeader + `
+load("@bazel_tools//tools/jdk:local_java_repository.bzl", "local_java_runtime")
+
+package(default_visibility = ["//visibility:public"])
+
+alias(
+    name = "jdk",
+    actual = "rbe_jdk",
+)
+
+local_java_runtime(
+    name = "rbe_jdk",
+    java_home = "{{ .JavaHome }}",
+    version = "{{ .JavaVersion }}",
+)
 `))
 
 	// javaBuildTemplate is the Java toolchain config BUILD file template for Bazel versions
-	// >=5.0.0 (tentative?).
+	// >=7.0.0 (including pre-releases).
+	// The difference between the older template is directly referencing to @rules_java
+	// instead of the indirection via @bazel_tools
 	javaBuildTemplate = template.Must(template.New("javaBuild").Parse(buildHeader + `
-load("@bazel_tools//tools/jdk:local_java_repository.bzl", "local_java_runtime")
+load("@rules_java//toolchains:local_java_repository.bzl", "local_java_runtime")
 
 package(default_visibility = ["//visibility:public"])
 
@@ -562,6 +583,25 @@ func UsesLocalJavaRuntime(bazelVersion string) (bool, error) {
 	return !bv.LessThan(*semver.New("5.0.0")), nil
 }
 
+func getJavaTemplate(o *Options) (*template.Template, error) {
+  usesNewJavaRule := o.JavaUseLocalRuntime
+	if !usesNewJavaRule {
+  	var err error
+		usesNewJavaRule, err = UsesLocalJavaRuntime(o.BazelVersion)
+    if (err != nil) {
+      return nil, fmt.Errorf("unable to determine what Java toolchain rule to use for Bazel %q: %w", o.BazelVersion, err)
+    }
+	}
+  if !usesNewJavaRule {
+    return legacyJavaBuildTemplate, nil
+	}
+	// use latest template if BazelVersion is unspecified
+  if o.BazelVersion != "" && o.BazelVersion < "7" {
+    return javaBuildTemplateLt7, nil
+  }
+  return javaBuildTemplate, nil
+}
+
 // genJavaConfigs returns a BUILD file containing a Java toolchain rule definition that contains
 // the following attributes determined by probing details about the JDK version installed in the
 // running toolchain container.
@@ -613,17 +653,11 @@ func genJavaConfigs(d *dockerRunner, o *Options) (generatedFile, error) {
 	}
 	log.Printf("Java version: '%s'.", javaVersion)
 
-	usesNewJavaRule := o.JavaUseLocalRuntime
-	if !usesNewJavaRule {
-		usesNewJavaRule, err = UsesLocalJavaRuntime(o.BazelVersion)
-		if err != nil {
-			return generatedFile{}, fmt.Errorf("unable to determine what Java toolchain rule to use for Bazel %q: %w", o.BazelVersion, err)
-		}
-	}
-	t := legacyJavaBuildTemplate
-	if usesNewJavaRule {
-		t = javaBuildTemplate
-	}
+	t, err := getJavaTemplate(o)
+  if err != nil {
+    return generatedFile{}, err
+  }
+
 	buf := bytes.NewBuffer(nil)
 	if err := t.Execute(buf, &javaBuildTemplateParams{
 		JavaHome:    javaHome,

pkg/rbeconfigsgen/rbeconfigsgen_test.go

@@ -16,6 +16,7 @@ package rbeconfigsgen
 
 import (
 	"testing"
+  "text/template"
 )
 
 func TestGenCppToolchainTarget(t *testing.T) {
@@ -84,3 +85,102 @@ func TestGenCppToolchainTarget(t *testing.T) {
 		})
 	}
 }
+
+func TestGetJavaTemplate(t *testing.T) {
+	tests := []struct {
+		name string
+		want *template.Template
+		opt  *Options
+	}{
+		{
+			name: "bazel 4, choose legacy",
+			want: legacyJavaBuildTemplate,
+			opt: &Options{
+        BazelVersion: "4.0.0",
+      },
+		},
+		{
+			name: "bazel 5, choose BazelLt7",
+			want: javaBuildTemplateLt7,
+			opt: &Options{
+        BazelVersion: "5.0.0",
+			},
+		},
+		{
+			name: "bazel 7, choose latest",
+			want: javaBuildTemplate,
+			opt: &Options{
+        BazelVersion: "7.0.0",
+			},
+		},
+		{
+			name: "bazel 7-pre, choose latest",
+			want: javaBuildTemplate,
+			opt: &Options{
+        BazelVersion: "7.0.0-pre.20230724.1",
+			},
+		},
+		{
+			name: "useLocalRuntime forced, choose latest",
+			want: javaBuildTemplate,
+			opt: &Options{
+			  JavaUseLocalRuntime: true,
+			},
+		},
+		{
+			name: "useLocalRuntime forced, bazel 4, choose BazelLt7",
+			want: javaBuildTemplateLt7,
+			opt: &Options{
+			  BazelVersion: "4.0.0",
+			  JavaUseLocalRuntime: true,
+			},
+		},
+		{
+			name: "useLocalRuntime forced, bazel 5, choose BazelLt7",
+			want: javaBuildTemplateLt7,
+			opt: &Options{
+			  BazelVersion: "5.0.0",
+			  JavaUseLocalRuntime: true,
+			},
+		},
+		{
+			name: "useLocalRuntime forced, bazel 6, choose BazelLt7",
+			want: javaBuildTemplateLt7,
+			opt: &Options{
+			  BazelVersion: "6.0.0",
+			  JavaUseLocalRuntime: true,
+			},
+		},
+		{
+			name: "useLocalRuntime forced, bazel 7, choose latest",
+			want: javaBuildTemplate,
+			opt: &Options{
+			  BazelVersion: "7.0.0",
+			  JavaUseLocalRuntime: true,
+			},
+		},
+		{
+			name: "useLocalRuntime forced, bazel 7-pre, choose latest",
+			want: javaBuildTemplate,
+			opt: &Options{
+			  BazelVersion: "7.0.0-pre.20200202",
+			  JavaUseLocalRuntime: true,
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			// We skip validation since we don't set all options required for
+			// regular execution.
+			got, err := getJavaTemplate(tc.opt);
+			if err != nil {
+			  t.Fatalf("getJavaTemplate failed: %v, wanted: %v", err, tc.want)
+			} else if got != tc.want {
+				t.Fatalf("getJavaTemplate: %v, wanted %v", got, tc.want)
+			}
+		})
+	}
+}

rules/exec_properties/exec_properties.bzl

@@ -203,7 +203,7 @@ PARAMS = {
     ),
 }
 
-def create_exec_properties_dict(**kwargs):
+def create_exec_properties_dict(**_kwargs):
     fail("create_exec_properties_dict is deprecated. Please use create_rbe_exec_properties_dict instead.")
 
 def create_rbe_exec_properties_dict(**kwargs):
@@ -242,7 +242,7 @@ def create_rbe_exec_properties_dict(**kwargs):
 
     return dict
 
-def merge_dicts(*dict_args):
+def merge_dicts(*_dict_args):
     fail("merge_dicts is deprecated. Please use dicts.add() instead. See https://github.com/bazelbuild/bazel-skylib/blob/master/docs/dicts_doc.md")
 
 def _exec_property_sets_repository_impl(repository_ctx):