Add --version support (#69)

.github/workflows/release.yml

@@ -13,7 +13,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - name: build
-        run: bazel build //target-determinator:all //driver:all && mkdir .release-artifacts && for f in $(bazel cquery --output=files 'let bins = kind(go_binary, //target-determinator:all  + //driver:all) in $bins - attr(tags, "\bmanual\b", $bins)'); do cp "$(bazel info execution_root)/${f}" .release-artifacts/; done
+        run: bazel build --stamp --workspace_status_command=./scripts/workspace-status.sh //target-determinator:all //driver:all && mkdir .release-artifacts && for f in $(bazel cquery --output=files 'let bins = kind(go_binary, //target-determinator:all  + //driver:all) in $bins - attr(tags, "\bmanual\b", $bins)'); do cp "$(bazel info execution_root)/${f}" .release-artifacts/; done
       - name: release
         uses: softprops/action-gh-release@v1
         with:

cli/BUILD.bazel

@@ -8,5 +8,6 @@ go_library(
     deps = [
         "//common",
         "//pkg",
+        "//version",
     ],
 )

cli/flags.go

@@ -4,11 +4,13 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	"os"
 	"path/filepath"
 	"strings"
 
 	"github.com/bazel-contrib/target-determinator/common"
 	"github.com/bazel-contrib/target-determinator/pkg"
+	"github.com/bazel-contrib/target-determinator/version"
 )
 
 type IgnoreFileFlag []common.RelPath
@@ -65,6 +67,7 @@ func (e *EnforceCleanFlag) Set(value string) error {
 }
 
 type CommonFlags struct {
+	Version                                bool
 	WorkingDirectory                       *string
 	BazelPath                              *string
 	BazelStartupOpts                       *MultipleStrings
@@ -86,6 +89,7 @@ func StrPtr() *string {
 
 func RegisterCommonFlags() *CommonFlags {
 	commonFlags := CommonFlags{
+		Version:                                false,
 		WorkingDirectory:                       StrPtr(),
 		BazelPath:                              StrPtr(),
 		BazelStartupOpts:                       &MultipleStrings{},
@@ -99,6 +103,7 @@ func RegisterCommonFlags() *CommonFlags {
 		CompareQueriesAroundAnalysisCacheClear: false,
 		FilterIncompatibleTargets:              true,
 	}
+	flag.BoolVar(&commonFlags.Version, "version", false, "Print the version of the tool and exit.")
 	flag.StringVar(commonFlags.WorkingDirectory, "working-directory", ".", "Working directory to query.")
 	flag.StringVar(commonFlags.BazelPath, "bazel", "bazel",
 		"Bazel binary (basename on $PATH, or absolute or relative path) to run.")
@@ -127,7 +132,12 @@ type CommonConfig struct {
 }
 
 // ValidateCommonFlags ensures that the argument follow the right format
-func ValidateCommonFlags() (targetPattern string, err error) {
+func ValidateCommonFlags(commandName string, flags *CommonFlags) (targetPattern string, err error) {
+	if flags.Version {
+		fmt.Printf("%s %s\n", commandName, version.Version)
+		os.Exit(0)
+	}
+
 	positional := flag.Args()
 	if len(positional) != 1 {
 		return "", fmt.Errorf("expected one positional argument, <before-revision>, but got %d", len(positional))

driver/driver.go

@@ -154,7 +154,7 @@ func parseFlags() (*driverFlags, error) {
 	}
 
 	var err error
-	flags.revisionBefore, err = cli.ValidateCommonFlags()
+	flags.revisionBefore, err = cli.ValidateCommonFlags("driver", flags.commonFlags)
 	if err != nil {
 		return nil, err
 	}

scripts/workspace-status.sh

@@ -0,0 +1,3 @@
+#!/bin/bash -eu
+
+echo "VERSION $(git describe --tags --exact-match)"

target-determinator/target-determinator.go

@@ -96,7 +96,7 @@ func parseFlags() (*targetDeterminatorFlags, error) {
 	flag.Parse()
 
 	var err error
-	flags.revisionBefore, err = cli.ValidateCommonFlags()
+	flags.revisionBefore, err = cli.ValidateCommonFlags("target-determinator", flags.commonFlags)
 	if err != nil {
 		return nil, err
 	}

version/BUILD.bazel

@@ -0,0 +1,11 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "version",
+    srcs = ["version.go"],
+    importpath = "github.com/bazel-contrib/target-determinator/version",
+    visibility = ["//visibility:public"],
+    x_defs = {
+        "Version": "{VERSION}",
+    },
+)

version/version.go

@@ -0,0 +1,4 @@
+package version
+
+// Version of target-determinator. This is set by `x_defs` in the owning go_library rule.
+var Version = "0.0.0-unstamped"