feat(releaser): release v1.5.0 — Node.js, multi-module Maven, configurable bump rules

- Add internal/node package: reads/writes package.json version (single or
  multi-path via node.package_json / node.package_jsons)
- Add maven.pom_paths support: update multiple pom.xml files in one release
  commit; pom_paths overrides pom_path; --pom flag clears pom_paths
- Add git.bump_rules config: per-type control of which version component bumps
  (breaking/feat/fix accept "patch" or "minor"); wired through version.Next()
  as a new sixth parameter
- Extract injectable function vars (absPath, gitAllCommits, gitCommitsSince,
  gitCommitFiles) to enable error-path testing without interfaces
- Achieve 100% per-package statement coverage across all 12 packages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/node/node.go

@@ -0,0 +1,42 @@
+package node
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+)
+
+// ReadVersion returns the version field from a package.json file.
+func ReadVersion(path string) (string, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return "", fmt.Errorf("read %s: %w", path, err)
+	}
+	var pkg struct {
+		Version string `json:"version"`
+	}
+	if err := json.Unmarshal(data, &pkg); err != nil {
+		return "", fmt.Errorf("parse %s: %w", path, err)
+	}
+	if pkg.Version == "" {
+		return "", fmt.Errorf("no version field in %s", path)
+	}
+	return pkg.Version, nil
+}
+
+// WriteVersion replaces the version field in a package.json file in-place.
+// oldVersion must match what ReadVersion returned. Formatting is preserved.
+func WriteVersion(path, oldVersion, newVersion string) error {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("read %s: %w", path, err)
+	}
+	old := `"version": "` + oldVersion + `"`
+	repl := `"version": "` + newVersion + `"`
+	if !strings.Contains(string(data), old) {
+		return fmt.Errorf("version %q not found in %s", oldVersion, path)
+	}
+	updated := strings.Replace(string(data), old, repl, 1)
+	return os.WriteFile(path, []byte(updated), 0644)
+}

internal/node/node_test.go

@@ -0,0 +1,99 @@
+package node
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func writeJSON(t *testing.T, content string) string {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "package.json")
+	if err := os.WriteFile(path, []byte(content), 0644); err != nil {
+		t.Fatal(err)
+	}
+	return path
+}
+
+const simplePackage = `{
+  "name": "my-app",
+  "version": "1.2.3",
+  "description": "test"
+}`
+
+func TestReadVersion(t *testing.T) {
+	got, err := ReadVersion(writeJSON(t, simplePackage))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if got != "1.2.3" {
+		t.Errorf("got %q, want 1.2.3", got)
+	}
+}
+
+func TestReadVersionMissingFile(t *testing.T) {
+	_, err := ReadVersion(filepath.Join(t.TempDir(), "package.json"))
+	if err == nil {
+		t.Error("expected error for missing file")
+	}
+}
+
+func TestReadVersionInvalidJSON(t *testing.T) {
+	_, err := ReadVersion(writeJSON(t, `{not valid json`))
+	if err == nil {
+		t.Error("expected error for invalid JSON")
+	}
+}
+
+func TestReadVersionNoVersionField(t *testing.T) {
+	_, err := ReadVersion(writeJSON(t, `{"name":"app"}`))
+	if err == nil {
+		t.Error("expected error when version field is absent")
+	}
+}
+
+func TestWriteVersion(t *testing.T) {
+	path := writeJSON(t, simplePackage)
+	if err := WriteVersion(path, "1.2.3", "1.2.4"); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	data, _ := os.ReadFile(path)
+	if !strings.Contains(string(data), `"version": "1.2.4"`) {
+		t.Errorf("expected updated version in file; got:\n%s", data)
+	}
+	// name and description must be preserved
+	if !strings.Contains(string(data), `"name": "my-app"`) {
+		t.Error("name field was lost")
+	}
+}
+
+func TestWriteVersionMissingFile(t *testing.T) {
+	err := WriteVersion(filepath.Join(t.TempDir(), "package.json"), "1.0.0", "1.0.1")
+	if err == nil {
+		t.Error("expected error for missing file")
+	}
+}
+
+func TestWriteVersionNotFound(t *testing.T) {
+	err := WriteVersion(writeJSON(t, simplePackage), "9.9.9", "9.9.10")
+	if err == nil {
+		t.Error("expected error when old version not found")
+	}
+}
+
+// FuzzReadVersion verifies ReadVersion never panics on arbitrary content.
+func FuzzReadVersion(f *testing.F) {
+	f.Add(simplePackage)
+	f.Add(`{}`)
+	f.Add(`{"version":"1.0.0"}`)
+	f.Add(`not json at all`)
+	f.Add(``)
+	f.Add("\x00\xff")
+
+	f.Fuzz(func(t *testing.T, content string) {
+		path := filepath.Join(t.TempDir(), "package.json")
+		os.WriteFile(path, []byte(content), 0644) //nolint:errcheck
+		ReadVersion(path)                          //nolint:errcheck
+	})
+}