cu diff (#135)

* cu diff

- Add support for `cu diff`
- Only show logs and diffs for changes that happened in the environment
- Move `cu log` code into Repository
- Add `cu log -p` and don't show patches by default
- Show notes in `cu log`

Signed-off-by: Andrea Luzzardi <andrea@luzzardi.com>

* cu log/diff: add tests

Signed-off-by: Andrea Luzzardi <andrea@luzzardi.com>

* Update environment/integration/repository_test.go

Co-authored-by: Tibor Vass <tiborvass@users.noreply.github.com>
Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

* Update environment/integration/repository_test.go

Co-authored-by: Tibor Vass <tiborvass@users.noreply.github.com>
Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

* Update environment/integration/repository_test.go

Co-authored-by: Tibor Vass <tiborvass@users.noreply.github.com>
Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

* cu log/diff: include stderr

Signed-off-by: Andrea Luzzardi <andrea@luzzardi.com>

---------

Signed-off-by: Andrea Luzzardi <andrea@luzzardi.com>
Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>
Co-authored-by: Tibor Vass <tiborvass@users.noreply.github.com>

Author: Andrea Luzzardi

cmd/cu/diff.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"os"
+
+	"github.com/dagger/container-use/repository"
+	"github.com/spf13/cobra"
+)
+
+var diffCmd = &cobra.Command{
+	Use:               "diff <env>",
+	Short:             "Show changes between the environment and the local branch",
+	Args:              cobra.ExactArgs(1),
+	ValidArgsFunction: suggestEnvironments,
+	RunE: func(app *cobra.Command, args []string) error {
+		ctx := app.Context()
+
+		// Ensure we're in a git repository
+		repo, err := repository.Open(ctx, ".")
+		if err != nil {
+			return err
+		}
+
+		return repo.Diff(ctx, args[0], os.Stdout)
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(diffCmd)
+}

cmd/cu/log.go

@@ -2,8 +2,6 @@ package main
 
 import (
 	"os"
-	"os/exec"
-	"strings"
 
 	"github.com/dagger/container-use/repository"
 	"github.com/spf13/cobra"
@@ -18,22 +16,18 @@ var logCmd = &cobra.Command{
 		ctx := app.Context()
 
 		// Ensure we're in a git repository
-		if _, err := repository.Open(ctx, "."); err != nil {
+		repo, err := repository.Open(ctx, ".")
+		if err != nil {
 			return err
 		}
 
-		env := args[0]
-		// prevent accidental single quotes to mess up command
-		env = strings.Trim(env, "'")
-		cmd := exec.CommandContext(app.Context(), "git", "log", "--patch", "container-use/"+env)
-		cmd.Stderr = os.Stderr
-		cmd.Stdin = os.Stdin
-		cmd.Stdout = os.Stdout
+		patch, _ := app.Flags().GetBool("patch")
 
-		return cmd.Run()
+		return repo.Log(ctx, args[0], patch, os.Stdout)
 	},
 }
 
 func init() {
+	logCmd.Flags().BoolP("patch", "p", false, "Generate patch")
 	rootCmd.AddCommand(logCmd)
 }

environment/integration/repository_test.go

@@ -1,6 +1,7 @@
 package integration
 
 import (
+	"bytes"
 	"context"
 	"os"
 	"strings"
@@ -126,3 +127,72 @@ func TestRepositoryCheckout(t *testing.T) {
 			"Expected branch to be %s or cu-%s, got %s", env.ID, env.ID, actualBranch)
 	})
 }
+
+// TestRepositoryLog tests retrieving commit history for an environment
+func TestRepositoryLog(t *testing.T) {
+	t.Parallel()
+	WithRepository(t, "repository-log", SetupEmptyRepo, func(t *testing.T, repo *repository.Repository, user *UserActions) {
+		ctx := context.Background()
+
+		// Create an environment and add some commits
+		env := user.CreateEnvironment("Test Log", "Testing repository log")
+		user.FileWrite(env.ID, "file1.txt", "initial content", "Initial commit")
+		user.FileWrite(env.ID, "file1.txt", "updated content", "Update file")
+		user.FileWrite(env.ID, "file2.txt", "new file", "Add second file")
+
+		// Get commit log without patches
+		var logBuf bytes.Buffer
+		err := repo.Log(ctx, env.ID, false, &logBuf)
+		logOutput := logBuf.String()
+		require.NoError(t, err, logOutput)
+
+		// Verify commit messages are present
+		assert.Contains(t, logOutput, "Add second file")
+		assert.Contains(t, logOutput, "Update file")
+		assert.Contains(t, logOutput, "Initial commit")
+
+		// Get commit log with patches
+		logBuf.Reset()
+		err = repo.Log(ctx, env.ID, true, &logBuf)
+		logWithPatchOutput := logBuf.String()
+		require.NoError(t, err, logWithPatchOutput)
+
+		// Verify patch information is included
+		assert.Contains(t, logWithPatchOutput, "diff --git")
+		assert.Contains(t, logWithPatchOutput, "+updated content")
+
+		// Test log for non-existent environment
+		err = repo.Log(ctx, "non-existent-env", false, &logBuf)
+		assert.Error(t, err)
+	})
+}
+
+// TestRepositoryDiff tests retrieving changes between commits
+func TestRepositoryDiff(t *testing.T) {
+	t.Parallel()
+	WithRepository(t, "repository-diff", SetupEmptyRepo, func(t *testing.T, repo *repository.Repository, user *UserActions) {
+		ctx := context.Background()
+
+		// Create an environment and make some changes
+		env := user.CreateEnvironment("Test Diff", "Testing repository diff")
+
+		// First commit - add a file
+		user.FileWrite(env.ID, "test.txt", "initial content\n", "Initial commit")
+
+		// Make changes to the file
+		user.FileWrite(env.ID, "test.txt", "initial content\nupdated content\n", "Update file")
+
+		// Get diff output
+		var diffBuf bytes.Buffer
+		err := repo.Diff(ctx, env.ID, &diffBuf)
+		diffOutput := diffBuf.String()
+		require.NoError(t, err, diffOutput)
+
+		// Verify diff contains expected changes
+		assert.Contains(t, diffOutput, "+updated content")
+
+		// Test diff with non-existent environment
+		err = repo.Diff(ctx, "non-existent-env", &diffBuf)
+		assert.Error(t, err)
+	})
+}

mcpserver/tools.go

@@ -128,6 +128,7 @@ type EnvironmentResponse struct {
 	RemoteRef       string                 `json:"remote_ref"`
 	CheckoutCommand string                 `json:"checkout_command_to_share_with_user"`
 	LogCommand      string                 `json:"log_command_to_share_with_user"`
+	DiffCommand     string                 `json:"diff_command_to_share_with_user"`
 	Services        []*environment.Service `json:"services,omitempty"`
 }
 
@@ -142,6 +143,7 @@ func marshalEnvironment(env *environment.Environment) (string, error) {
 		RemoteRef:       fmt.Sprintf("container-use/%s", env.ID),
 		CheckoutCommand: fmt.Sprintf("cu checkout %s", env.ID),
 		LogCommand:      fmt.Sprintf("cu log %s", env.ID),
+		DiffCommand:     fmt.Sprintf("cu diff %s", env.ID),
 		Services:        env.Services,
 	}
 	out, err := json.Marshal(resp)

repository/git.go

@@ -235,6 +235,33 @@ func (r *Repository) addGitNote(ctx context.Context, env *environment.Environmen
 	return r.propagateGitNotes(ctx, gitNotesLogRef)
 }
 
+func (r *Repository) currentUserBranch(ctx context.Context) (string, error) {
+	return RunGitCommand(ctx, r.userRepoPath, "branch", "--show-current")
+}
+
+func (r *Repository) mergeBase(ctx context.Context, env *environment.EnvironmentInfo) (string, error) {
+	currentBranch, err := r.currentUserBranch(ctx)
+	if err != nil {
+		return "", err
+	}
+	currentBranch = strings.TrimSpace(currentBranch)
+	envGitRef := fmt.Sprintf("%s/%s", containerUseRemote, env.ID)
+	mergeBase, err := RunGitCommand(ctx, r.userRepoPath, "merge-base", currentBranch, envGitRef)
+	if err != nil {
+		return "", err
+	}
+	return strings.TrimSpace(mergeBase), nil
+}
+
+func (r *Repository) revisionRange(ctx context.Context, env *environment.EnvironmentInfo) (string, error) {
+	mergeBase, err := r.mergeBase(ctx, env)
+	if err != nil {
+		return "", err
+	}
+	envGitRef := fmt.Sprintf("%s/%s", containerUseRemote, env.ID)
+	return fmt.Sprintf("%s..%s", mergeBase, envGitRef), nil
+}
+
 func (r *Repository) commitWorktreeChanges(ctx context.Context, worktreePath, name, explanation string) error {
 	status, err := RunGitCommand(ctx, worktreePath, "status", "--porcelain")
 	if err != nil {

repository/repository.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"log/slog"
 	"os"
 	"os/exec"
@@ -354,3 +355,62 @@ func (r *Repository) Checkout(ctx context.Context, id, branch string) (string, e
 
 	return branch, err
 }
+
+func (r *Repository) Log(ctx context.Context, id string, patch bool, w io.Writer) error {
+	envInfo, err := r.Info(ctx, id)
+	if err != nil {
+		return err
+	}
+
+	logArgs := []string{
+		"git",
+		"log",
+		fmt.Sprintf("--notes=%s", gitNotesLogRef),
+	}
+
+	if patch {
+		logArgs = append(logArgs, "--patch")
+	}
+
+	revisionRange, err := r.revisionRange(ctx, envInfo)
+	if err != nil {
+		return err
+	}
+
+	logArgs = append(logArgs, revisionRange)
+
+	cmd := exec.CommandContext(ctx, "git")
+	cmd.Dir = r.userRepoPath
+	cmd.Args = logArgs
+	cmd.Stdout = w
+	cmd.Stderr = w
+
+	return cmd.Run()
+}
+
+func (r *Repository) Diff(ctx context.Context, id string, w io.Writer) error {
+	envInfo, err := r.Info(ctx, id)
+	if err != nil {
+		return err
+	}
+
+	diffArgs := []string{
+		"git",
+		"diff",
+	}
+
+	revisionRange, err := r.revisionRange(ctx, envInfo)
+	if err != nil {
+		return err
+	}
+
+	diffArgs = append(diffArgs, revisionRange)
+
+	cmd := exec.CommandContext(ctx, "git")
+	cmd.Dir = r.userRepoPath
+	cmd.Args = diffArgs
+	cmd.Stdout = w
+	cmd.Stderr = w
+
+	return cmd.Run()
+}