🌱 parse go.mod with modfile.Parse

Signed-off-by: Alexandre Mahdhaoui <alexandre.mahdhaoui@gmail.com>

Makefile

@@ -94,7 +94,7 @@ $(GOLANGCI_LINT): # Build golangci-lint from tools folder.
 
 GO_MOD_CHECK_DIR := $(abspath ./hack/tools/cmd/gomodcheck)
 GO_MOD_CHECK := $(abspath $(TOOLS_BIN_DIR)/gomodcheck)
-GO_MOD_CHECK_IGNORE := $(abspath ./hack/.gomodcheck.yaml)
+GO_MOD_CHECK_IGNORE := $(abspath .gomodcheck.yaml)
 .PHONY: $(GO_MOD_CHECK)
 $(GO_MOD_CHECK): # Build gomodcheck
 	go build -C $(GO_MOD_CHECK_DIR) -o $(GO_MOD_CHECK)
@@ -149,5 +149,3 @@ APIDIFF_OLD_COMMIT ?= $(shell git rev-parse origin/main)
 .PHONY: apidiff
 verify-apidiff: $(GO_APIDIFF) ## Check for API differences
 	$(GO_APIDIFF) $(APIDIFF_OLD_COMMIT) --print-compatible
-
-

go.mod

@@ -30,6 +30,8 @@ require (
 	sigs.k8s.io/yaml v1.3.0
 )
 
+require golang.org/x/mod v0.15.0
+
 require (
 	github.com/antlr4-go/antlr/v4 v4.13.0 // indirect
 	github.com/asaskevich/govalidator v0.0.0-20190424111038-f61b66f89f4a // indirect

go.sum

@@ -156,6 +156,8 @@ golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc h1:mCRnTeVUjcrhlRmO0VK8a6k6R
 golang.org/x/exp v0.0.0-20230515195305-f3d0a9c9a5cc/go.mod h1:V1LtkGg67GoY2N1AnLN78QLrzxkLyJw7RJb1gzOOz9w=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.15.0 h1:SernR4v+D55NyBH2QiEQrlBAnj1ECL6AGrA5+dPaMY8=
+golang.org/x/mod v0.15.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=

hack/tools/cmd/gomodcheck/main.go

@@ -5,10 +5,10 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
-	"regexp"
 	"strings"
 
 	"go.uber.org/zap"
+	"golang.org/x/mod/modfile"
 	"sigs.k8s.io/yaml"
 )
 
@@ -17,8 +17,8 @@ const (
 )
 
 type config struct {
-	UpstreamRefs    []string `yaml:"upstreamRefs"`
-	ExcludedModules []string `yaml:"excludedModules"`
+	UpstreamRefs    []string `json:"upstreamRefs"`
+	ExcludedModules []string `json:"excludedModules"`
 }
 
 type upstream struct {
@@ -45,12 +45,12 @@ func main() {
 	// --- 1. parse config
 	b, err := os.ReadFile(os.Args[1])
 	if err != nil {
-		logger.Fatal(err.Error())
+		fatal(err)
 	}
 
 	cfg := new(config)
 	if err := yaml.Unmarshal(b, cfg); err != nil {
-		logger.Fatal(err.Error())
+		fatal(err)
 	}
 
 	excludedMods := make(map[string]any)
@@ -59,15 +59,15 @@ func main() {
 	}
 
 	// --- 2. project mods
-	deps, err := parseModFile()
+	projectModules, err := modulesFromGoModFile()
 	if err != nil {
-		logger.Fatal(err.Error())
+		fatal(err)
 	}
 
-	// --- 3. upstream mods (holding upstream refs)
-	upstreamModGraph, err := getUpstreamModGraph(cfg.UpstreamRefs)
+	// --- 3. upstream mods
+	upstreamModules, err := modulesFromUpstreamModGraph(cfg.UpstreamRefs)
 	if err != nil {
-		logger.Fatal(err.Error())
+		fatal(err)
 	}
 
 	oosMods := make([]oosMod, 0)
@@ -78,13 +78,13 @@ func main() {
 	// then for each upstream module,
 	// if project module version doesn't match upstream version,
 	// then we add the version and the ref to the list of out of sync modules.
-	for mod, version := range deps {
+	for mod, version := range projectModules {
 		if _, ok := excludedMods[mod]; ok {
 			logger.Infof("skipped excluded module: %s", mod)
 			continue
 		}
 
-		if versionToRef, ok := upstreamModGraph[mod]; ok {
+		if versionToRef, ok := upstreamModules[mod]; ok {
 			upstreams := make([]upstream, 0)
 
 			for upstreamVersion, upstreamRef := range versionToRef {
@@ -107,97 +107,94 @@ func main() {
 	}
 
 	if len(oosMods) == 0 {
-		fmt.Println("Success! 🎉")
+		fmt.Println("🎉 Success!")
 		os.Exit(0)
 	}
 
 	b, err = json.MarshalIndent(map[string]any{"outOfSyncModules": oosMods}, "", "  ")
 	if err != nil {
-		panic(err)
+		fatal(err)
 	}
 
 	fmt.Println(string(b))
 	os.Exit(1)
 }
 
-var (
-	cleanMods     = regexp.MustCompile(`\t| *//.*`)
-	modDelimStart = regexp.MustCompile(`^require.*`)
-	modDelimEnd   = ")"
-)
-
-func parseModFile() (map[string]string, error) {
+func modulesFromGoModFile() (map[string]string, error) {
 	b, err := os.ReadFile(modFile)
 	if err != nil {
 		return nil, err
 	}
 
-	in := string(cleanMods.ReplaceAll(b, []byte("")))
-	out := make(map[string]string)
-
-	start := false
-	for _, s := range strings.Split(in, "\n") {
-		switch {
-		case modDelimStart.MatchString(s) && !start:
-			start = true
-		case s == modDelimEnd:
-			return out, nil
-		case start:
-			kv := strings.SplitN(s, " ", 2)
-			if len(kv) < 2 {
-				return nil, fmt.Errorf("unexpected format for module: %q", s)
-			}
+	f, err := modfile.Parse(modFile, b, nil)
+	if err != nil {
+		return nil, err
+	}
 
-			out[kv[0]] = kv[1]
-		}
+	out := make(map[string]string)
+	for _, mod := range f.Require {
+		out[mod.Mod.Path] = mod.Mod.Version
 	}
 
 	return out, nil
 }
 
-func getUpstreamModGraph(upstreamRefs []string) (map[string]map[string]string, error) {
+func modulesFromUpstreamModGraph(upstreamRefList []string) (map[string]map[string]string, error) {
 	b, err := exec.Command("go", "mod", "graph").Output()
 	if err != nil {
 		return nil, err
 	}
 
 	graph := string(b)
-	o1Refs := make(map[string]bool)
-	for _, upstreamRef := range upstreamRefs {
-		o1Refs[upstreamRef] = false
+
+	// upstreamRefs is a set of user specified upstream modules.
+	// The set has 2 functions:
+	//   1. Check if `go mod graph` modules are one of the user specified upstream modules.
+	//   2. Mark if a user specified upstream module was found in the module graph.
+	// If a user specified upstream module is not found, gomodcheck will exit with an error.
+	upstreamRefs := make(map[string]bool)
+	for _, ref := range upstreamRefList {
+		upstreamRefs[ref] = false
 	}
 
 	modToVersionToUpstreamRef := make(map[string]map[string]string)
-
 	for _, line := range strings.Split(graph, "\n") {
-		upstreamRef := strings.SplitN(line, "@", 2)[0]
-		if _, ok := o1Refs[upstreamRef]; ok {
-			o1Refs[upstreamRef] = true
-			kv := strings.SplitN(strings.SplitN(line, " ", 2)[1], "@", 2)
-			name := kv[0]
-			version := kv[1]
-
-			if m, ok := modToVersionToUpstreamRef[kv[0]]; ok {
-				m[version] = upstreamRef
-			} else {
-				versionToRef := map[string]string{version: upstreamRef}
-				modToVersionToUpstreamRef[name] = versionToRef
-			}
+		ref := strings.SplitN(line, "@", 2)[0]
+
+		if _, ok := upstreamRefs[ref]; !ok {
+			continue
 		}
+
+		upstreamRefs[ref] = true // mark the ref as found
+
+		kv := strings.SplitN(strings.SplitN(line, " ", 2)[1], "@", 2)
+		name := kv[0]
+		version := kv[1]
+
+		if _, ok := modToVersionToUpstreamRef[name]; !ok {
+			modToVersionToUpstreamRef[name] = make(map[string]string)
+		}
+
+		modToVersionToUpstreamRef[name][version] = ref
 	}
 
-	notFound := ""
-	for ref, found := range o1Refs {
+	notFoundErr := ""
+	for ref, found := range upstreamRefs {
 		if !found {
-			notFound = fmt.Sprintf("%s%s, ", notFound, ref)
+			notFoundErr = fmt.Sprintf("%s%s, ", notFoundErr, ref)
 		}
 	}
 
-	if notFound != "" {
-		return nil, fmt.Errorf("cannot verify modules;"+
-			"the following specified upstream module cannot be found in go.mod: [ %s ]",
-			strings.TrimSuffix(notFound, ", "))
+	if notFoundErr != "" {
+		return nil, fmt.Errorf("cannot verify modules: "+
+			"the following specified upstream module(s) cannot be found in go.mod: [ %s ]",
+			strings.TrimSuffix(notFoundErr, ", "))
 	}
 
 	return modToVersionToUpstreamRef, nil
 }
+
+func fatal(err error) {
+	fmt.Printf("❌ %s\n", err.Error())
+	os.Exit(1)
+}