Remove var buildInfo (nginx#2358)

Problem: Running the tests in parallel would cause a data race, because
the tests were all trying to write the same variable.

Solution: Remove the var and type, that were only used for tests and use
the actual build info to test that the function works correctly.

Author: miledxz

Makefile

@@ -181,7 +181,7 @@ lint: check-golangci-lint ## Run golangci-lint against code
 .PHONY: unit-test
 unit-test: ## Run unit tests for the go code
 	# We have to run the tests in the cmd package using `go test` because of a bug with the CLI library cobra. See https://github.com/spf13/cobra/issues/2104.
-	go test ./cmd/... -race -shuffle=on -coverprofile=cmd-coverage.out -covermode=atomic
+	go test -buildvcs ./cmd/... -race -shuffle=on -coverprofile=cmd-coverage.out -covermode=atomic
 	go run github.com/onsi/ginkgo/v2/ginkgo --randomize-all --randomize-suites --race --keep-going --fail-on-pending --trace --covermode=atomic --coverprofile=coverage.out -r internal
 	go tool cover -html=coverage.out -o cover.html
 	go tool cover -html=cmd-coverage.out -o cmd-cover.html

cmd/gateway/commands.go

@@ -501,16 +501,12 @@ func parseFlags(flags *pflag.FlagSet) ([]string, []string) {
 	return flagKeys, flagValues
 }
 
-type buildInfoFunc func() (info *debug.BuildInfo, ok bool)
-
-var buildInfo buildInfoFunc = debug.ReadBuildInfo
-
 func getBuildInfo() (commitHash string, commitTime string, dirtyBuild string) {
 	commitHash = "unknown"
 	commitTime = "unknown"
 	dirtyBuild = "unknown"
 
-	info, ok := buildInfo()
+	info, ok := debug.ReadBuildInfo()
 	if !ok {
 		return
 	}

cmd/gateway/commands_test.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"io"
-	"runtime/debug"
 	"testing"
 
 	. "github.com/onsi/gomega"
@@ -585,57 +584,16 @@ func TestParseFlags(t *testing.T) {
 }
 
 func TestGetBuildInfo(t *testing.T) {
+	t.Parallel()
 	g := NewWithT(t)
-	stubBuildInfo := func() (info *debug.BuildInfo, ok bool) {
-		return &debug.BuildInfo{
-			Settings: []debug.BuildSetting{
-				{Key: "vcs.revision", Value: "abc123"},
-				{Key: "vcs.time", Value: "2024-07-30T12:34:56Z"},
-				{Key: "vcs.modified", Value: "true"},
-			},
-		}, true
-	}
-
-	buildInfo = stubBuildInfo
-
-	commitHash, commitTime, dirtyBuild := getBuildInfo()
-
-	g.Expect(commitHash).To(Equal("abc123"))
-	g.Expect(commitTime).To(Equal("2024-07-30T12:34:56Z"))
-	g.Expect(dirtyBuild).To(Equal("true"))
-}
-
-func TestGetBuildInfoNoBuildInfo(t *testing.T) {
-	g := NewWithT(t)
-	stubBuildInfo := func() (info *debug.BuildInfo, ok bool) {
-		return nil, false
-	}
-
-	buildInfo = stubBuildInfo
 
 	commitHash, commitTime, dirtyBuild := getBuildInfo()
 
-	g.Expect(commitHash).To(Equal("unknown"))
-	g.Expect(commitTime).To(Equal("unknown"))
-	g.Expect(dirtyBuild).To(Equal("unknown"))
-}
-
-func TestGetBuildInfoMissingValue(t *testing.T) {
-	g := NewWithT(t)
-	stubBuildInfo := func() (info *debug.BuildInfo, ok bool) {
-		return &debug.BuildInfo{
-			Settings: []debug.BuildSetting{
-				{Key: "vcs.time", Value: "2024-07-30T12:34:56Z"},
-				{Key: "vcs.modified", Value: "true"},
-			},
-		}, true
-	}
-
-	buildInfo = stubBuildInfo
-
-	commitHash, commitTime, dirtyBuild := getBuildInfo()
+	g.Expect(commitHash).To(Not(BeEmpty()))
+	g.Expect(commitTime).To(Not(BeEmpty()))
+	g.Expect(dirtyBuild).To(Not(BeEmpty()))
 
-	g.Expect(commitHash).To(Equal("unknown"))
-	g.Expect(commitTime).To(Equal("2024-07-30T12:34:56Z"))
-	g.Expect(dirtyBuild).To(Equal("true"))
+	g.Expect(commitHash).To(Not(Equal("unknown")))
+	g.Expect(commitTime).To(Not(Equal("unknown")))
+	g.Expect(dirtyBuild).To(Not(Equal("unknown")))
 }