feat(platforms): fallback to x86_64 before bazel version 4.1.0 on App… (

bazelbuild#299)

* feat(platforms): fallback to x86_64 before bazel version 4.1.0 on Apple Silicon

* add test target in BUILD

* fix build

* rm return value err

* refactor: add log, rename sem_ver to semver

* refactor: add log

platforms/BUILD

@@ -1,8 +1,17 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
     srcs = ["platforms.go"],
     importpath = "github.com/bazelbuild/bazelisk/platforms",
     visibility = ["//visibility:public"],
+    deps = [
+        "@com_github_hashicorp_go_version//:go_default_library",
+    ],
+)
+
+go_test(
+    name = "platforms_test",
+    srcs = ["platforms_test.go"],
+    embed = [":go_default_library"],
 )

platforms/platforms.go

@@ -3,6 +3,8 @@ package platforms
 
 import (
 	"fmt"
+	semver "github.com/hashicorp/go-version"
+	"log"
 	"runtime"
 )
 
@@ -43,10 +45,30 @@ func DetermineBazelFilename(version string, includeSuffix bool) (string, error)
 		return "", fmt.Errorf("unsupported operating system \"%s\", must be Linux, macOS or Windows", runtime.GOOS)
 	}
 
+	if osName == "darwin" {
+		machineName = DarwinFallback(machineName, version)
+	}
+
 	var filenameSuffix string
 	if includeSuffix {
 		filenameSuffix = DetermineExecutableFilenameSuffix()
 	}
 
 	return fmt.Sprintf("bazel-%s-%s-%s%s", version, osName, machineName, filenameSuffix), nil
 }
+
+// DarwinFallback Darwin arm64 was supported since 4.1.0, before 4.1.0, fall back to x86_64
+func DarwinFallback(machineName string, version string) (alterMachineName string) {
+	v, err := semver.NewVersion(version)
+	if err != nil {
+		return machineName
+	}
+
+	armSupportVer, _ := semver.NewVersion("4.1.0")
+
+	if machineName == "arm64" && v.LessThan(armSupportVer) {
+		log.Printf("WARN: Fallback to x86_64 because arm64 is not supported on Apple Silicon until 4.1.0")
+		return "x86_64"
+	}
+	return machineName
+}

platforms/platforms_test.go

@@ -0,0 +1,56 @@
+package platforms
+
+import "testing"
+
+func TestDarwinFallback(t *testing.T) {
+	type args struct {
+		machineName string
+		version     string
+	}
+	tests := []struct {
+		name                 string
+		args                 args
+		wantAlterMachineName string
+	}{
+		{
+			name: "before 4.1.0, x86_64 do not fallback",
+			args: args{
+				machineName: "x86_64",
+				version:     "4.0.1",
+			},
+			wantAlterMachineName: "x86_64",
+		},
+		{
+			name: "since 4.1.0, x86_64 do not fallback either",
+			args: args{
+				machineName: "x86_64",
+				version:     "4.1.0",
+			},
+			wantAlterMachineName: "x86_64",
+		},
+		{
+			name: "before 4.1.0, arm64 not supported, fallback to x86_64 on arm64",
+			args: args{
+				machineName: "arm64",
+				version:     "4.0.1",
+			},
+			wantAlterMachineName: "x86_64",
+		},
+		{
+			name: "since 4.1.0, arm64 supported, do not fallback",
+			args: args{
+				machineName: "arm64",
+				version:     "4.1.0",
+			},
+			wantAlterMachineName: "arm64",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotAlterMachineName := DarwinFallback(tt.args.machineName, tt.args.version)
+			if gotAlterMachineName != tt.wantAlterMachineName {
+				t.Errorf("DarwinFallback() gotAlterMachineName = %v, want %v", gotAlterMachineName, tt.wantAlterMachineName)
+			}
+		})
+	}
+}