Fix lint issues in metadata package

Extract readTimeFields helper to reduce cyclomatic complexity,
convert if-else chain to switch statement, and add test constants
for repeated string literals.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: mble

metadata/metadata.go

@@ -157,10 +157,40 @@ func (m *Metadata) ToJSON() ([]byte, error) {
 	return out, nil
 }
 
+// readTimeFields reads all timestamp-related fields from the archive header.
+func readTimeFields(m *Metadata, readInt func(string) (int, error)) error {
+	const yearStart = 1900
+	var err error
+
+	if m.TimeSec, err = readInt("timeSec"); err != nil {
+		return err
+	}
+	if m.TimeMin, err = readInt("timeMin"); err != nil {
+		return err
+	}
+	if m.TimeHour, err = readInt("timeHour"); err != nil {
+		return err
+	}
+	if m.TimeDay, err = readInt("timeDay"); err != nil {
+		return err
+	}
+	if m.TimeMonth, err = readInt("timeMonth"); err != nil {
+		return err
+	}
+	yearOffset, err := readInt("timeYearOffset")
+	if err != nil {
+		return err
+	}
+	m.TimeYear = yearStart + yearOffset
+	if m.TimeIsDST, err = readInt("timeIsDst"); err != nil {
+		return err
+	}
+	return nil
+}
+
 // NewMetadata reads from reader, parsing out the pg_dump archive header format
 // into a Metadata struct.
 func NewMetadata(reader io.Reader) (Metadata, error) {
-	const yearStart = 1900
 	metadata := Metadata{}
 
 	r := bufio.NewReader(reader)
@@ -223,48 +253,28 @@ func NewMetadata(reader io.Reader) (Metadata, error) {
 	// Version 1.16+ (PostgreSQL 16+) changed the format again - the compression algorithm
 	// is stored as a single byte indicator.
 	const versionWithCompressionSpec = (1 << 16) | (15 << 8) // 1.15
-	const versionWithNewCompression = (1 << 16) | (16 << 8) // 1.16
-	if metadata.ArchiveVersion() >= versionWithNewCompression {
+	const versionWithNewCompression = (1 << 16) | (16 << 8)  // 1.16
+	archiveVersion := metadata.ArchiveVersion()
+	switch {
+	case archiveVersion >= versionWithNewCompression:
 		// Format 1.16+: Read single-byte compression algorithm indicator
 		compressionAlgo, readErr := ReadExactInt(r, 1)
 		if readErr != nil {
 			return metadata, readErr
 		}
 		metadata.Compression = int(compressionAlgo)
-	} else if metadata.ArchiveVersion() >= versionWithCompressionSpec {
+	case archiveVersion >= versionWithCompressionSpec:
 		// Format 1.15.x: Compression is a string specification
 		if metadata.CompressionSpec, err = metadata.ReadString(r); err != nil {
 			return metadata, err
 		}
-	} else {
+	default:
 		// Older formats use an integer for compression level
 		if metadata.Compression, err = readIntField("compression"); err != nil {
 			return metadata, err
 		}
 	}
-	if metadata.TimeSec, err = readIntField("timeSec"); err != nil {
-		return metadata, err
-	}
-	if metadata.TimeMin, err = readIntField("timeMin"); err != nil {
-		return metadata, err
-	}
-	if metadata.TimeHour, err = readIntField("timeHour"); err != nil {
-		return metadata, err
-	}
-	if metadata.TimeDay, err = readIntField("timeDay"); err != nil {
-		return metadata, err
-	}
-	if metadata.TimeMonth, err = readIntField("timeMonth"); err != nil {
-		return metadata, err
-	}
-
-	yearOffset, err := readIntField("timeYearOffset")
-	if err != nil {
-		return metadata, err
-	}
-	metadata.TimeYear = yearStart + yearOffset
-
-	if metadata.TimeIsDST, err = readIntField("timeIsDst"); err != nil {
+	if err = readTimeFields(&metadata, readIntField); err != nil { //nolint:gocritic // reusing err is clearer here
 		return metadata, err
 	}
 	if metadata.DatabaseName, err = metadata.ReadString(r); err != nil {

metadata/metadata_test.go

@@ -10,6 +10,14 @@ import (
 	"github.com/mble/pgdump-metadata-extractor/metadata"
 )
 
+const (
+	testDBName     = "test_db"
+	testVersion    = "10.11"
+	testVersionPG  = "14.0"
+	testVersionPG2 = "16.0"
+	testVersionPG3 = "17.0"
+)
+
 func strPtr(s string) *string {
 	return &s
 }
@@ -163,8 +171,8 @@ func TestNewMetadata(t *testing.T) {
 		TimeYear:      2021,
 		TimeIsDST:     1,
 		DatabaseName:  strPtr("empty_db"),
-		RemoteVersion: strPtr("10.11"),
-		PGDumpVersion: strPtr("10.11"),
+		RemoteVersion: strPtr(testVersion),
+		PGDumpVersion: strPtr(testVersion),
 		TOCCount:      15,
 	}
 
@@ -189,8 +197,8 @@ func TestNewMetadataIntSize8(t *testing.T) {
 
 	intSize := 8
 	db := "empty_db"
-	remote := "10.11"
-	pgDump := "10.11"
+	remote := testVersion
+	pgDump := testVersion
 
 	var buf bytes.Buffer
 	buf.WriteString("PGDMP")
@@ -235,8 +243,8 @@ func TestNewMetadataIntSize8(t *testing.T) {
 		TimeYear:      2021,
 		TimeIsDST:     1,
 		DatabaseName:  strPtr("empty_db"),
-		RemoteVersion: strPtr("10.11"),
-		PGDumpVersion: strPtr("10.11"),
+		RemoteVersion: strPtr(testVersion),
+		PGDumpVersion: strPtr(testVersion),
 		TOCCount:      15,
 	}
 
@@ -359,7 +367,7 @@ func TestNewMetadataFormat115(t *testing.T) {
 
 	// Format 1.15 uses compression as a string
 	intSize := 4
-	db := "test_db"
+	db := testDBName
 	remote := "14.0"
 	pgDump := "14.0"
 	compressionSpec := "none"
@@ -406,7 +414,7 @@ func TestNewMetadataFormat115(t *testing.T) {
 		TimeMonth:       6,
 		TimeYear:        2021,
 		TimeIsDST:       1,
-		DatabaseName:    strPtr("test_db"),
+		DatabaseName:    strPtr(testDBName),
 		RemoteVersion:   strPtr("14.0"),
 		PGDumpVersion:   strPtr("14.0"),
 		TOCCount:        15,
@@ -422,7 +430,7 @@ func TestNewMetadataFormat116(t *testing.T) {
 
 	// Format 1.16 uses compression as a single byte
 	intSize := 4
-	db := "test_db"
+	db := testDBName
 	remote := "16.0"
 	pgDump := "17.0"
 
@@ -468,7 +476,7 @@ func TestNewMetadataFormat116(t *testing.T) {
 		TimeMonth:     8,
 		TimeYear:      2025,
 		TimeIsDST:     1,
-		DatabaseName:  strPtr("test_db"),
+		DatabaseName:  strPtr(testDBName),
 		RemoteVersion: strPtr("16.0"),
 		PGDumpVersion: strPtr("17.0"),
 		TOCCount:      10,
@@ -499,8 +507,8 @@ func TestToJSON(t *testing.T) {
 		TimeYear:      2021,
 		TimeIsDST:     1,
 		DatabaseName:  strPtr("empty_db"),
-		RemoteVersion: strPtr("10.11"),
-		PGDumpVersion: strPtr("10.11"),
+		RemoteVersion: strPtr(testVersion),
+		PGDumpVersion: strPtr(testVersion),
 		TOCCount:      15,
 	}