ref: dc110eaaf376c02fd957853330566a75b1511f3c
parent: 5797711751b1da63648ecf3e597d7418b256d5c8
author: Runxi Yu <me@runxiyu.org>
date: Fri Feb 20 17:50:40 EST 2026
config: Import from the previous version and fix test harnesses
--- /dev/null
+++ b/config/config.go
@@ -1,0 +1,498 @@
+// Package config provides routines to parse Git configuration files.
+package config
+
+import (
+ "bufio"
+ "bytes"
+ "errors"
+ "fmt"
+ "io"
+ "strings"
+ "unicode"
+)
+
+// Config holds all parsed configuration entries from a Git config file.
+//
+// A Config preserves the ordering of entries as they appeared in the source.
+//
+// Lookups are matched case-insensitively for section and key names, and
+// subsections must match exactly.
+//
+// Includes aren't supported yet; they will be supported in a later revision.
+type Config struct {+ entries []ConfigEntry
+}
+
+// ConfigEntry represents a single parsed configuration directive.
+type ConfigEntry struct {+ // The section name in canonical lowercase form.
+ Section string
+ // The subsection name, retaining the exact form parsed from the input.
+ Subsection string
+ // The key name in canonical lowercase form.
+ Key string
+ // The interpreted value of the configuration entry, including unescaped
+ // characters where appropriate.
+ Value string
+}
+
+// ParseConfig reads and parses Git configuration entries from r.
+func ParseConfig(r io.Reader) (*Config, error) {+ parser := &configParser{+ reader: bufio.NewReader(r),
+ lineNum: 1,
+ }
+ return parser.parse()
+}
+
+// Get retrieves the first value for a given section, optional subsection, and key.
+// Returns an empty string if not found.
+func (c *Config) Get(section, subsection, key string) string {+ section = strings.ToLower(section)
+ key = strings.ToLower(key)
+ for _, entry := range c.entries {+ if strings.EqualFold(entry.Section, section) &&
+ entry.Subsection == subsection &&
+ strings.EqualFold(entry.Key, key) {+ return entry.Value
+ }
+ }
+ return ""
+}
+
+// GetAll retrieves all values for a given section, optional subsection, and key.
+func (c *Config) GetAll(section, subsection, key string) []string {+ section = strings.ToLower(section)
+ key = strings.ToLower(key)
+ var values []string
+ for _, entry := range c.entries {+ if strings.EqualFold(entry.Section, section) &&
+ entry.Subsection == subsection &&
+ strings.EqualFold(entry.Key, key) {+ values = append(values, entry.Value)
+ }
+ }
+ return values
+}
+
+// Entries returns a copy of all parsed configuration entries in the order they
+// appeared. Modifying the returned slice does not affect the Config.
+func (c *Config) Entries() []ConfigEntry {+ result := make([]ConfigEntry, len(c.entries))
+ copy(result, c.entries)
+ return result
+}
+
+type configParser struct {+ reader *bufio.Reader
+ lineNum int
+ currentSection string
+ currentSubsec string
+ peeked rune
+ hasPeeked bool
+}
+
+func (p *configParser) parse() (*Config, error) {+ cfg := &Config{}+
+ if err := p.skipBOM(); err != nil {+ return nil, err
+ }
+
+ for {+ ch, err := p.nextChar()
+ if err == io.EOF {+ break
+ }
+ if err != nil {+ return nil, err
+ }
+
+ // Skip whitespace and newlines
+ if ch == '\n' || unicode.IsSpace(ch) {+ continue
+ }
+
+ // Comments
+ if ch == '#' || ch == ';' {+ if err := p.skipToEOL(); err != nil && err != io.EOF {+ return nil, err
+ }
+ continue
+ }
+
+ // Section header
+ if ch == '[' {+ if err := p.parseSection(); err != nil {+ return nil, fmt.Errorf("furgit: config: line %d: %w", p.lineNum, err)+ }
+ continue
+ }
+
+ // Key-value pair
+ if unicode.IsLetter(ch) {+ p.unreadChar(ch)
+ if err := p.parseKeyValue(cfg); err != nil {+ return nil, fmt.Errorf("furgit: config: line %d: %w", p.lineNum, err)+ }
+ continue
+ }
+
+ return nil, fmt.Errorf("furgit: config: line %d: unexpected character %q", p.lineNum, ch)+ }
+
+ return cfg, nil
+}
+
+func (p *configParser) nextChar() (rune, error) {+ if p.hasPeeked {+ p.hasPeeked = false
+ return p.peeked, nil
+ }
+
+ ch, _, err := p.reader.ReadRune()
+ if err != nil {+ return 0, err
+ }
+
+ if ch == '\r' {+ next, _, err := p.reader.ReadRune()
+ if err == nil && next == '\n' {+ ch = '\n'
+ } else if err == nil {+ // Weird but ok
+ _ = p.reader.UnreadRune()
+ }
+ }
+
+ if ch == '\n' {+ p.lineNum++
+ }
+
+ return ch, nil
+}
+
+func (p *configParser) unreadChar(ch rune) {+ p.peeked = ch
+ p.hasPeeked = true
+ if ch == '\n' && p.lineNum > 1 {+ p.lineNum--
+ }
+}
+
+func (p *configParser) skipBOM() error {+ first, _, err := p.reader.ReadRune()
+ if err == io.EOF {+ return nil
+ }
+ if err != nil {+ return err
+ }
+ if first != '\uFEFF' {+ _ = p.reader.UnreadRune()
+ }
+ return nil
+}
+
+func (p *configParser) skipToEOL() error {+ for {+ ch, err := p.nextChar()
+ if err != nil {+ return err
+ }
+ if ch == '\n' {+ return nil
+ }
+ }
+}
+
+func (p *configParser) parseSection() error {+ var name bytes.Buffer
+
+ for {+ ch, err := p.nextChar()
+ if err != nil {+ return errors.New("unexpected EOF in section header")+ }
+
+ if ch == ']' {+ section := name.String()
+ if !isValidSection(section) {+ return fmt.Errorf("invalid section name: %q", section)+ }
+ p.currentSection = strings.ToLower(section)
+ p.currentSubsec = ""
+ return nil
+ }
+
+ if unicode.IsSpace(ch) {+ return p.parseExtendedSection(&name)
+ }
+
+ if !isKeyChar(ch) && ch != '.' {+ return fmt.Errorf("invalid character in section name: %q", ch)+ }
+
+ name.WriteRune(unicode.ToLower(ch))
+ }
+}
+
+func (p *configParser) parseExtendedSection(sectionName *bytes.Buffer) error {+ for {+ ch, err := p.nextChar()
+ if err != nil {+ return errors.New("unexpected EOF in section header")+ }
+ if !unicode.IsSpace(ch) {+ if ch != '"' {+ return errors.New("expected quote after section name")+ }
+ break
+ }
+ }
+
+ var subsec bytes.Buffer
+ for {+ ch, err := p.nextChar()
+ if err != nil {+ return errors.New("unexpected EOF in subsection")+ }
+
+ if ch == '\n' {+ return errors.New("newline in subsection")+ }
+
+ if ch == '"' {+ break
+ }
+
+ if ch == '\\' {+ next, err := p.nextChar()
+ if err != nil {+ return errors.New("unexpected EOF after backslash in subsection")+ }
+ if next == '\n' {+ return errors.New("newline after backslash in subsection")+ }
+ subsec.WriteRune(next)
+ } else {+ subsec.WriteRune(ch)
+ }
+ }
+
+ ch, err := p.nextChar()
+ if err != nil {+ return errors.New("unexpected EOF after subsection")+ }
+ if ch != ']' {+ return fmt.Errorf("expected ']' after subsection, got %q", ch)+ }
+
+ section := sectionName.String()
+ if !isValidSection(section) {+ return fmt.Errorf("invalid section name: %q", section)+ }
+
+ p.currentSection = strings.ToLower(section)
+ p.currentSubsec = subsec.String()
+ return nil
+}
+
+func (p *configParser) parseKeyValue(cfg *Config) error {+ if p.currentSection == "" {+ return errors.New("key-value pair before any section header")+ }
+
+ var key bytes.Buffer
+ for {+ ch, err := p.nextChar()
+ if err != nil {+ return errors.New("unexpected EOF reading key")+ }
+
+ if ch == '=' || ch == '\n' || unicode.IsSpace(ch) {+ p.unreadChar(ch)
+ break
+ }
+
+ if !isKeyChar(ch) {+ return fmt.Errorf("invalid character in key: %q", ch)+ }
+
+ key.WriteRune(unicode.ToLower(ch))
+ }
+
+ keyStr := key.String()
+ if len(keyStr) == 0 {+ return errors.New("empty key name")+ }
+ if !unicode.IsLetter(rune(keyStr[0])) {+ return errors.New("key must start with a letter")+ }
+
+ for {+ ch, err := p.nextChar()
+ if err == io.EOF {+ cfg.entries = append(cfg.entries, ConfigEntry{+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: "true",
+ })
+ return nil
+ }
+ if err != nil {+ return err
+ }
+
+ if ch == '\n' {+ cfg.entries = append(cfg.entries, ConfigEntry{+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: "true",
+ })
+ return nil
+ }
+
+ if ch == '#' || ch == ';' {+ if err := p.skipToEOL(); err != nil && err != io.EOF {+ return err
+ }
+ cfg.entries = append(cfg.entries, ConfigEntry{+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: "true",
+ })
+ return nil
+ }
+
+ if ch == '=' {+ break
+ }
+
+ if !unicode.IsSpace(ch) {+ return fmt.Errorf("unexpected character after key: %q", ch)+ }
+ }
+
+ value, err := p.parseValue()
+ if err != nil {+ return err
+ }
+
+ cfg.entries = append(cfg.entries, ConfigEntry{+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: value,
+ })
+
+ return nil
+}
+
+func (p *configParser) parseValue() (string, error) {+ var value bytes.Buffer
+ var inQuote bool
+ var inComment bool
+ trimLen := 0
+
+ for {+ ch, err := p.nextChar()
+ if err == io.EOF {+ if inQuote {+ return "", errors.New("unexpected EOF in quoted value")+ }
+ if trimLen > 0 {+ return value.String()[:trimLen], nil
+ }
+ return value.String(), nil
+ }
+ if err != nil {+ return "", err
+ }
+
+ if ch == '\n' {+ if inQuote {+ return "", errors.New("newline in quoted value")+ }
+ if trimLen > 0 {+ return value.String()[:trimLen], nil
+ }
+ return value.String(), nil
+ }
+
+ if inComment {+ continue
+ }
+
+ if unicode.IsSpace(ch) && !inQuote {+ if trimLen == 0 && value.Len() > 0 {+ trimLen = value.Len()
+ }
+ if value.Len() > 0 {+ value.WriteRune(ch)
+ }
+ continue
+ }
+
+ if !inQuote && (ch == '#' || ch == ';') {+ inComment = true
+ continue
+ }
+
+ if trimLen > 0 {+ trimLen = 0
+ }
+
+ if ch == '\\' {+ next, err := p.nextChar()
+ if err == io.EOF {+ return "", errors.New("unexpected EOF after backslash")+ }
+ if err != nil {+ return "", err
+ }
+
+ switch next {+ case '\n':
+ continue
+ case 'n':
+ value.WriteRune('\n')+ case 't':
+ value.WriteRune('\t')+ case 'b':
+ value.WriteRune('\b')+ case '\\', '"':
+ value.WriteRune(next)
+ default:
+ return "", fmt.Errorf("invalid escape sequence: \\%c", next)+ }
+ continue
+ }
+
+ if ch == '"' {+ inQuote = !inQuote
+ continue
+ }
+
+ value.WriteRune(ch)
+ }
+}
+
+func isValidSection(s string) bool {+ if len(s) == 0 {+ return false
+ }
+ for _, ch := range s {+ if !unicode.IsLetter(ch) && !unicode.IsDigit(ch) && ch != '-' && ch != '.' {+ return false
+ }
+ }
+ return true
+}
+
+func isKeyChar(ch rune) bool {+ return unicode.IsLetter(ch) || unicode.IsDigit(ch) || ch == '-'
+}
--- /dev/null
+++ b/config/config_test.go
@@ -1,0 +1,275 @@
+package config
+
+import (
+ "os"
+ "path/filepath"
+ "strings"
+ "testing"
+
+ "codeberg.org/lindenii/furgit/internal/testgit"
+ "codeberg.org/lindenii/furgit/oid"
+)
+
+func openConfig(t *testing.T, repo *testgit.TestRepo) *os.File {+ t.Helper()
+ cfgFile, err := os.Open(filepath.Join(repo.Dir(), "config"))
+ if err != nil {+ t.Fatalf("failed to open config: %v", err)+ }
+ return cfgFile
+}
+
+func gitConfigGet(t *testing.T, repo *testgit.TestRepo, key string) string {+ t.Helper()
+ return repo.Run(t, "config", "--get", key)
+}
+
+func TestConfigAgainstGit(t *testing.T) {+ testgit.ForEachAlgorithm(t, func(t *testing.T, algo oid.Algorithm) {+ repo := testgit.NewBareRepo(t, algo)
+ repo.Run(t, "config", "core.bare", "true")
+ repo.Run(t, "config", "core.filemode", "false")
+ repo.Run(t, "config", "user.name", "Jane Doe")
+ repo.Run(t, "config", "user.email", "jane@example.org")
+
+ cfgFile := openConfig(t, repo)
+ defer func() { _ = cfgFile.Close() }()+
+ cfg, err := ParseConfig(cfgFile)
+ if err != nil {+ t.Fatalf("ParseConfig failed: %v", err)+ }
+
+ if got := cfg.Get("core", "", "bare"); got != "true" {+ t.Errorf("core.bare: got %q, want %q", got, "true")+ }
+ if got := cfg.Get("core", "", "filemode"); got != "false" {+ t.Errorf("core.filemode: got %q, want %q", got, "false")+ }
+ if got := cfg.Get("user", "", "name"); got != "Jane Doe" {+ t.Errorf("user.name: got %q, want %q", got, "Jane Doe")+ }
+ if got := cfg.Get("user", "", "email"); got != "jane@example.org" {+ t.Errorf("user.email: got %q, want %q", got, "jane@example.org")+ }
+ })
+}
+
+func TestConfigSubsectionAgainstGit(t *testing.T) {+ testgit.ForEachAlgorithm(t, func(t *testing.T, algo oid.Algorithm) {+ repo := testgit.NewBareRepo(t, algo)
+ repo.Run(t, "config", "remote.origin.url", "https://example.org/repo.git")
+ repo.Run(t, "config", "remote.origin.fetch", "+refs/heads/*:refs/remotes/origin/*")
+
+ cfgFile := openConfig(t, repo)
+ defer func() { _ = cfgFile.Close() }()+
+ cfg, err := ParseConfig(cfgFile)
+ if err != nil {+ t.Fatalf("ParseConfig failed: %v", err)+ }
+
+ if got := cfg.Get("remote", "origin", "url"); got != "https://example.org/repo.git" {+ t.Errorf("remote.origin.url: got %q, want %q", got, "https://example.org/repo.git")+ }
+ if got := cfg.Get("remote", "origin", "fetch"); got != "+refs/heads/*:refs/remotes/origin/*" {+ t.Errorf("remote.origin.fetch: got %q, want %q", got, "+refs/heads/*:refs/remotes/origin/*")+ }
+ })
+}
+
+func TestConfigMultiValueAgainstGit(t *testing.T) {+ testgit.ForEachAlgorithm(t, func(t *testing.T, algo oid.Algorithm) {+ repo := testgit.NewBareRepo(t, algo)
+ repo.Run(t, "config", "--add", "remote.origin.fetch", "+refs/heads/main:refs/remotes/origin/main")
+ repo.Run(t, "config", "--add", "remote.origin.fetch", "+refs/heads/dev:refs/remotes/origin/dev")
+ repo.Run(t, "config", "--add", "remote.origin.fetch", "+refs/tags/*:refs/tags/*")
+
+ cfgFile := openConfig(t, repo)
+ defer func() { _ = cfgFile.Close() }()+
+ cfg, err := ParseConfig(cfgFile)
+ if err != nil {+ t.Fatalf("ParseConfig failed: %v", err)+ }
+
+ fetches := cfg.GetAll("remote", "origin", "fetch")+ if len(fetches) != 3 {+ t.Fatalf("expected 3 fetch values, got %d", len(fetches))+ }
+
+ expected := []string{+ "+refs/heads/main:refs/remotes/origin/main",
+ "+refs/heads/dev:refs/remotes/origin/dev",
+ "+refs/tags/*:refs/tags/*",
+ }
+ for i, want := range expected {+ if fetches[i] != want {+ t.Errorf("fetch[%d]: got %q, want %q", i, fetches[i], want)+ }
+ }
+ })
+}
+
+func TestConfigCaseInsensitiveAgainstGit(t *testing.T) {+ testgit.ForEachAlgorithm(t, func(t *testing.T, algo oid.Algorithm) {+ repo := testgit.NewBareRepo(t, algo)
+ repo.Run(t, "config", "Core.Bare", "true")
+ repo.Run(t, "config", "CORE.FileMode", "false")
+
+ gitVerifyBare := gitConfigGet(t, repo, "core.bare")
+ gitVerifyFilemode := gitConfigGet(t, repo, "core.filemode")
+
+ cfgFile := openConfig(t, repo)
+ defer func() { _ = cfgFile.Close() }()+
+ cfg, err := ParseConfig(cfgFile)
+ if err != nil {+ t.Fatalf("ParseConfig failed: %v", err)+ }
+
+ if got := cfg.Get("core", "", "bare"); got != gitVerifyBare {+ t.Errorf("core.bare: got %q, want %q (from git)", got, gitVerifyBare)+ }
+ if got := cfg.Get("CORE", "", "BARE"); got != gitVerifyBare {+ t.Errorf("CORE.BARE: got %q, want %q (from git)", got, gitVerifyBare)+ }
+ if got := cfg.Get("core", "", "filemode"); got != gitVerifyFilemode {+ t.Errorf("core.filemode: got %q, want %q (from git)", got, gitVerifyFilemode)+ }
+ })
+}
+
+func TestConfigBooleanAgainstGit(t *testing.T) {+ testgit.ForEachAlgorithm(t, func(t *testing.T, algo oid.Algorithm) {+ repo := testgit.NewBareRepo(t, algo)
+ repo.Run(t, "config", "test.flag1", "true")
+ repo.Run(t, "config", "test.flag2", "false")
+ repo.Run(t, "config", "test.flag3", "yes")
+ repo.Run(t, "config", "test.flag4", "no")
+
+ cfgFile := openConfig(t, repo)
+ defer func() { _ = cfgFile.Close() }()+
+ cfg, err := ParseConfig(cfgFile)
+ if err != nil {+ t.Fatalf("ParseConfig failed: %v", err)+ }
+
+ tests := []struct {+ key string
+ want string
+ }{+ {"flag1", gitConfigGet(t, repo, "test.flag1")},+ {"flag2", gitConfigGet(t, repo, "test.flag2")},+ {"flag3", gitConfigGet(t, repo, "test.flag3")},+ {"flag4", gitConfigGet(t, repo, "test.flag4")},+ }
+
+ for _, tt := range tests {+ if got := cfg.Get("test", "", tt.key); got != tt.want {+ t.Errorf("test.%s: got %q, want %q (from git)", tt.key, got, tt.want)+ }
+ }
+ })
+}
+
+func TestConfigComplexValuesAgainstGit(t *testing.T) {+ testgit.ForEachAlgorithm(t, func(t *testing.T, algo oid.Algorithm) {+ repo := testgit.NewBareRepo(t, algo)
+ repo.Run(t, "config", "test.spaced", "value with spaces")
+ repo.Run(t, "config", "test.special", "value=with=equals")
+ repo.Run(t, "config", "test.path", "/path/to/something")
+ repo.Run(t, "config", "test.number", "12345")
+
+ cfgFile := openConfig(t, repo)
+ defer func() { _ = cfgFile.Close() }()+
+ cfg, err := ParseConfig(cfgFile)
+ if err != nil {+ t.Fatalf("ParseConfig failed: %v", err)+ }
+
+ tests := []string{"spaced", "special", "path", "number"}+ for _, key := range tests {+ want := gitConfigGet(t, repo, "test."+key)
+ if got := cfg.Get("test", "", key); got != want {+ t.Errorf("test.%s: got %q, want %q (from git)", key, got, want)+ }
+ }
+ })
+}
+
+func TestConfigEntriesAgainstGit(t *testing.T) {+ testgit.ForEachAlgorithm(t, func(t *testing.T, algo oid.Algorithm) {+ repo := testgit.NewBareRepo(t, algo)
+ repo.Run(t, "config", "core.bare", "true")
+ repo.Run(t, "config", "core.filemode", "false")
+ repo.Run(t, "config", "user.name", "Test User")
+
+ cfgFile := openConfig(t, repo)
+ defer func() { _ = cfgFile.Close() }()+
+ cfg, err := ParseConfig(cfgFile)
+ if err != nil {+ t.Fatalf("ParseConfig failed: %v", err)+ }
+
+ entries := cfg.Entries()
+ if len(entries) < 3 {+ t.Errorf("expected at least 3 entries, got %d", len(entries))+ }
+
+ found := make(map[string]bool)
+ for _, entry := range entries {+ key := entry.Section + "." + entry.Key
+ if entry.Subsection != "" {+ key = entry.Section + "." + entry.Subsection + "." + entry.Key
+ }
+ found[key] = true
+
+ gitValue := gitConfigGet(t, repo, key)
+ if entry.Value != gitValue {+ t.Errorf("entry %s: got value %q, git has %q", key, entry.Value, gitValue)+ }
+ }
+ })
+}
+
+func TestConfigErrorCases(t *testing.T) {+ tests := []struct {+ name string
+ config string
+ }{+ {+ name: "key before section",
+ config: "bare = true",
+ },
+ {+ name: "invalid section character",
+ config: "[core/invalid]",
+ },
+ {+ name: "unterminated section",
+ config: "[core",
+ },
+ {+ name: "unterminated quote",
+ config: "[core]\n\tbare = \"true",
+ },
+ {+ name: "invalid escape",
+ config: "[core]\n\tvalue = \"test\\x\"",
+ },
+ }
+
+ for _, tt := range tests {+ t.Run(tt.name, func(t *testing.T) {+ r := strings.NewReader(tt.config)
+ _, err := ParseConfig(r)
+ if err == nil {+ t.Errorf("expected error for %s", tt.name)+ }
+ })
+ }
+}
--
⑨