crosslink: Add work command (#311)

* Add go.work files to Git ignore

* Add test_data temp files to Git ignore

* Add Work with failing tests

* Fix tests

* Add work command

* Update changelog

* Implement Work

* Fix flags

* Create go.work when missing

* Refactor tests

* Fix typo

* Add gowork Make target

* Fix gitignore

* Uninted want go.work content

* Fix insertUses comment

* Apply suggestions from code review

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>

* refactor: Add forGoModules function

* Update crosslink/README.md

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>

* Update common.go

* Update crosslink/internal/work_test.go

Co-authored-by: bryan-aguilar <46550959+bryan-aguilar@users.noreply.github.com>

* Document go flag

* Add go version validation

---------

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
Co-authored-by: Tyler Yahn <MrAlias@users.noreply.github.com>
Co-authored-by: bryan-aguilar <46550959+bryan-aguilar@users.noreply.github.com>

.chloggen/crosslink-work.yaml

@@ -0,0 +1,16 @@
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. crosslink)
+component: crosslink
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Add work command generating go.work file."
+
+# One or more tracking issues related to the change
+issues: [309]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

.gitignore

@@ -7,6 +7,11 @@ Thumbs.db
 *.iml
 *.so
 coverage.*
+/go.work
+go.work.sum
+
+crosslink/internal/test_data/
+!crosslink/internal/test_data/.placeholder
 
 checkdoc/checkdoc
 chloggen/chloggen

Makefile

@@ -208,3 +208,8 @@ chlog-update: | $(CHLOGGEN)
 crosslink: | $(CROSSLINK)
 	@echo "Updating intra-repository dependencies in all go modules" \
 		&& $(CROSSLINK) --root=$(shell pwd) --prune
+
+.PHONY: gowork
+gowork: | $(CROSSLINK)
+	$(CROSSLINK) work --root=$(shell pwd)
+

crosslink/README.md

@@ -3,6 +3,8 @@
 Crosslink is a tool to assist in managing go repositories that contain multiple
 intra-repository `go.mod` files. Crosslink automatically scans and inserts
 replace statements for direct and transitive intra-repository dependencies.
+Crosslink can generate a `go.work` file to facilitate local development of a
+repository containing multiple Go modules.
 Crosslink also contains functionality to remove any extra replace statements
 that are no longer required within reason (see below).
 
@@ -128,3 +130,17 @@ Can be disabled when overwriting.
 
 **Quick Tip: Make sure your `go.mod` files are tracked and committed in a VCS
 before running crosslink.**
+
+### work
+
+Creates or updates existing `go.work` file by adding use statements
+for all intra-repository Go modules. It also removes use statements
+for out-dated intra-repository Go modules.
+
+    crosslink work --root=/users/foo/multimodule-go-repo
+
+### --go
+
+ Go version applied when new `go.work` file is created (default "1.19").
+
+    crosslink work --go=1.20

crosslink/cmd/root.go

@@ -33,6 +33,7 @@ type commandConfig struct {
 	excludeFlags []string
 	rootCommand  cobra.Command
 	pruneCommand cobra.Command
+	workCommand  cobra.Command
 }
 
 func newCommandConfig() *commandConfig {
@@ -68,8 +69,8 @@ func newCommandConfig() *commandConfig {
 				return fmt.Errorf("could not create zap logger: %w", err)
 			}
 		}
-		return nil
 
+		return nil
 	}
 
 	postRunSetup := func(cmd *cobra.Command, args []string) error {
@@ -105,6 +106,16 @@ func newCommandConfig() *commandConfig {
 		},
 	}
 	c.rootCommand.AddCommand(&c.pruneCommand)
+
+	c.workCommand = cobra.Command{
+		Use:   "work",
+		Short: "Generate or update the go.work file with use statements for intra-repository dependencies",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return cl.Work(c.runConfig)
+		},
+	}
+	c.rootCommand.AddCommand(&c.workCommand)
+
 	return c
 }
 
@@ -123,14 +134,16 @@ func Execute() {
 }
 
 func init() {
-
 	comCfg.rootCommand.PersistentFlags().StringVar(&comCfg.runConfig.RootPath, "root", "", `path to root directory of multi-module repository. If --root flag is not provided crosslink will attempt to find a
 	git repository in the current or a parent directory.`)
-	comCfg.rootCommand.PersistentFlags().StringSliceVar(&comCfg.excludeFlags, "exclude", []string{}, "list of comma separated go modules that crosslink will ignore in operations."+
-		"multiple calls of --exclude can be made")
 	comCfg.rootCommand.PersistentFlags().BoolVarP(&comCfg.runConfig.Verbose, "verbose", "v", false, "verbose output")
+	comCfg.rootCommand.Flags().StringSliceVar(&comCfg.excludeFlags, "exclude", []string{}, "list of comma separated go modules that crosslink will ignore in operations."+
+		"multiple calls of --exclude can be made")
 	comCfg.rootCommand.Flags().BoolVar(&comCfg.runConfig.Overwrite, "overwrite", false, "overwrite flag allows crosslink to make destructive (replacing or updating) actions to existing go.mod files")
 	comCfg.rootCommand.Flags().BoolVarP(&comCfg.runConfig.Prune, "prune", "p", false, "enables pruning operations on all go.mod files inside root repository")
+	comCfg.pruneCommand.Flags().StringSliceVar(&comCfg.excludeFlags, "exclude", []string{}, "list of comma separated go modules that crosslink will ignore in operations."+
+		"multiple calls of --exclude can be made")
+	comCfg.workCommand.Flags().StringVar(&comCfg.runConfig.GoVersion, "go", "1.19", "Go version applied when new go.work file is created")
 }
 
 // transform array slice into map

crosslink/internal/common.go

@@ -16,9 +16,11 @@ package crosslink
 
 import (
 	"fmt"
+	"io/fs"
 	"os"
 	"path/filepath"
 
+	"go.uber.org/zap"
 	"golang.org/x/mod/modfile"
 )
 
@@ -53,3 +55,24 @@ func writeModule(module *moduleInfo) error {
 
 	return nil
 }
+
+// forGoModules iterates the fn for all Go modules under rootPath.
+// The path argument of fn function is the path to the go.mod file
+// relative to rootPath (e.g. go.mod, submodule/go.mod).
+func forGoModules(logger *zap.Logger, rootPath string, fn func(path string) error) error {
+	return fs.WalkDir(os.DirFS(rootPath), ".", func(path string, dir fs.DirEntry, err error) error {
+		if err != nil {
+			logger.Warn("File could not be read during fs.WalkDir",
+				zap.Error(err),
+				zap.String("path", path))
+			return nil
+		}
+
+		// find Go module
+		if dir.Name() != "go.mod" {
+			return nil
+		}
+
+		return fn(path)
+	})
+}

crosslink/internal/config.go

@@ -39,6 +39,7 @@ type RunConfig struct {
 	ExcludedPaths map[string]struct{}
 	Overwrite     bool
 	Prune         bool
+	GoVersion     string
 	Logger        *zap.Logger
 }
 

crosslink/internal/graph.go

@@ -16,7 +16,6 @@ package crosslink
 
 import (
 	"fmt"
-	"io/fs"
 	"os"
 	"path/filepath"
 	"strings"
@@ -31,34 +30,23 @@ import (
 func buildDepedencyGraph(rc RunConfig, rootModulePath string) (map[string]*moduleInfo, error) {
 	moduleMap := make(map[string]*moduleInfo)
 
-	goModFunc := func(filePath string, info fs.FileInfo, err error) error {
+	err := forGoModules(rc.Logger, rc.RootPath, func(path string) error {
+		fullPath := filepath.Join(rc.RootPath, path)
+		modFile, err := os.ReadFile(filepath.Clean(fullPath))
 		if err != nil {
-			rc.Logger.Error("File could not be read during filePath.Walk",
-				zap.Error(err),
-				zap.String("file_path", filePath))
-
-			return nil
+			return fmt.Errorf("failed to read file: %w", err)
 		}
 
-		if filepath.Base(filePath) == "go.mod" {
-			modFile, err := os.ReadFile(filepath.Clean(filePath))
-			if err != nil {
-				return fmt.Errorf("failed to read file: %w", err)
-			}
-
-			modContents, err := modfile.Parse(filePath, modFile, nil)
-			if err != nil {
-				rc.Logger.Error("Modfile could not be parsed",
-					zap.Error(err),
-					zap.String("file_path", filePath))
-			}
-
-			moduleMap[modfile.ModulePath(modFile)] = newModuleInfo(*modContents)
+		modContents, err := modfile.Parse(fullPath, modFile, nil)
+		if err != nil {
+			rc.Logger.Error("Modfile could not be parsed",
+				zap.Error(err),
+				zap.String("file_path", path))
 		}
-		return nil
-	}
 
-	err := filepath.Walk(rc.RootPath, goModFunc)
+		moduleMap[modfile.ModulePath(modFile)] = newModuleInfo(*modContents)
+		return nil
+	})
 	if err != nil {
 		return nil, fmt.Errorf("failed during file walk: %w", err)
 	}

crosslink/internal/mock_test_data/testWork/go.work

@@ -0,0 +1,13 @@
+go 1.19
+
+// existing valid use statements under root should remain
+use ./testA
+
+// invalid use statements under root should be removed ONLY if prune is used
+use ./testC
+
+// use statements outside the root should remain
+use ../other-module
+
+// replace statements should remain
+replace foo.opentelemetery.io/bar => ../bar

crosslink/internal/mock_test_data/testWork/gomod

@@ -0,0 +1,3 @@
+module go.opentelemetry.io/build-tools/crosslink/testroot
+
+go 1.19

crosslink/internal/mock_test_data/testWork/testA/gomod

@@ -0,0 +1,3 @@
+module go.opentelemetry.io/build-tools/crosslink/testroot/testA
+
+go 1.19

crosslink/internal/mock_test_data/testWork/testB/gomod

@@ -0,0 +1,3 @@
+module go.opentelemetry.io/build-tools/crosslink/testroot/testB
+
+go 1.19