wolfictl pmub: just a reverse of wolfictl bump

pkg/cli/bump.go

@@ -15,9 +15,10 @@ import (
 const epochPattern = `epoch: %d`
 
 type bumpOptions struct {
-	repoDir string
-	epoch   bool
-	dryRun  bool
+	repoDir   string
+	epoch     bool
+	dryRun    bool
+	increment bool
 }
 
 // this feels very hacky but the Makefile is going away with help from Dag so plan to delete this func soon
@@ -72,6 +73,14 @@ the version in each matching configuration file:
     wolfictl bump openssl
     wolfictl bump lib*.yaml
 
+wolfictl bump can take a filename, a package or a file glob,
+and extra flag increment set to false , decreasing the version in each
+matching configuration file:
+
+    wolfictl bump --increment=false zlib.yaml
+    wolfictl bump --increment=false openssl
+    wolfictl bump --increment=false lib*.yaml
+
 The command assumes it is being run from the top of the wolfi/os
 repository. To look for files in another location use the --repo flag.
 You can use --dry-run to see which versions will be bumped without
@@ -120,6 +129,7 @@ modifying anything in the filesystem.
 	cmd.Flags().BoolVar(&opts.epoch, "epoch", true, "bump the package epoch")
 	cmd.Flags().BoolVar(&opts.dryRun, "dry-run", false, "don't change anything, just print what would be done")
 	cmd.Flags().StringVar(&opts.repoDir, "repo", ".", "path to the wolfi/os repository")
+	cmd.Flags().BoolVar(&opts.increment, "increment", true, "increments/decrements the package epoch")
 
 	return cmd
 }
@@ -130,9 +140,14 @@ func bumpEpoch(ctx context.Context, opts bumpOptions, path string) error {
 		return fmt.Errorf("unable to parse configuration at %q: %w", path, err)
 	}
 
+	newEpoch := cfg.Package.Epoch + 1
+	if !opts.increment {
+		newEpoch = cfg.Package.Epoch - 1
+	}
+
 	fmt.Fprintf(
 		os.Stderr, "bumping %s-%s-%d in %s to epoch %d\n", cfg.Package.Name,
-		cfg.Package.Version, cfg.Package.Epoch, path, cfg.Package.Epoch+1,
+		cfg.Package.Version, cfg.Package.Epoch, path, newEpoch,
 	)
 
 	if opts.dryRun {
@@ -154,7 +169,7 @@ func bumpEpoch(ctx context.Context, opts bumpOptions, path string) error {
 			found = true
 			newFile = append(
 				newFile, strings.ReplaceAll(
-					scanner.Text(), old, fmt.Sprintf(epochPattern, cfg.Package.Epoch+1),
+					scanner.Text(), old, fmt.Sprintf(epochPattern, newEpoch),
 				),
 			)
 		} else {
@@ -173,7 +188,7 @@ func bumpEpoch(ctx context.Context, opts bumpOptions, path string) error {
 		return fmt.Errorf("writing %s: %w", path, err)
 	}
 
-	if err := updateMakefile(opts.repoDir, cfg.Package.Name, cfg.Package.Version, cfg.Package.Epoch+1); err != nil {
+	if err := updateMakefile(opts.repoDir, cfg.Package.Name, cfg.Package.Version, newEpoch); err != nil {
 		return fmt.Errorf("updating makefile: %w", err)
 	}
 

pkg/cli/bump_test.go

@@ -0,0 +1,100 @@
+package cli
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gopkg.in/yaml.v3"
+)
+
+func TestBumpEpoch(t *testing.T) {
+	ctx := context.Background()
+
+	// Create a temporary directory for testing
+	tmpDir, err := os.MkdirTemp("", "test")
+	if err != nil {
+		t.Fatalf("Error creating temp directory: %v", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	// Create a temporary config file with a known epoch
+	configFilePath := filepath.Join(tmpDir, "test_config.yaml")
+	configContent := `
+package:
+  name: clickhouse
+  version: 24.2.1.2248
+  epoch: 6
+`
+	err = os.WriteFile(configFilePath, []byte(configContent), 0o600)
+	if err != nil {
+		t.Fatalf("Error creating temp config file: %v", err)
+	}
+
+	tests := []struct {
+		desc            string
+		increment       bool
+		expectedEpoch   int
+		expectedMessage string
+	}{
+		{
+			desc:          "Incrementing epoch",
+			increment:     true,
+			expectedEpoch: 7,
+			expectedMessage: "bumping clickhouse-24.2.1.2248-0 in " + configFilePath +
+				" to epoch 7\n",
+		},
+		{
+			desc:          "Decrementing epoch",
+			increment:     false,
+			expectedEpoch: 6,
+			expectedMessage: "bumping clickhouse-24.2.1.2248-0 in " + configFilePath +
+				" to epoch 6\n",
+		},
+		{
+			desc:          "Decrementing epoch",
+			increment:     false,
+			expectedEpoch: 5,
+			expectedMessage: "bumping clickhouse-24.2.1.2248-0 in " + configFilePath +
+				" to epoch 5\n",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.desc, func(t *testing.T) {
+			opts := bumpOptions{
+				repoDir:   tmpDir,
+				dryRun:    false,
+				increment: tc.increment,
+			}
+
+			// Test bumping epoch
+			err := bumpEpoch(ctx, opts, configFilePath)
+			if err != nil {
+				t.Fatalf("Error bumping epoch: %v", err)
+			}
+
+			// Read the modified config file to check if the epoch is bumped
+			modifiedConfigData, err := os.ReadFile(configFilePath)
+			if err != nil {
+				t.Fatalf("Error reading modified config file: %v", err)
+			}
+
+			var modifiedConfig map[string]interface{}
+			err = yaml.Unmarshal(modifiedConfigData, &modifiedConfig)
+			if err != nil {
+				t.Fatalf("Error unmarshalling modified config: %v", err)
+			}
+
+			actualEpoch, ok := modifiedConfig["package"].(map[string]interface{})["epoch"].(int)
+			if !ok {
+				t.Fatalf("Error retrieving actual epoch from modified config")
+			}
+
+			if actualEpoch != tc.expectedEpoch {
+				t.Errorf("Epoch not bumped correctly. Expected: %d, Got: %d", tc.expectedEpoch, actualEpoch)
+			}
+		})
+	}
+}