Finish up gitignore implementation

tools/ignorefiles/api.go

@@ -0,0 +1,25 @@
+package ignorefiles
+
+import (
+	"fmt"
+	"io"
+	"io/fs"
+)
+
+var _ = fmt.Print
+
+type IgnoreFile interface {
+	LoadString(string) error
+	LoadBytes([]byte) error
+	LoadLines(...string) error
+	LoadFile(io.Reader) error
+	LoadPath(string) error
+
+	// relpath is the path relative to the directory containing the ignorefile.
+	// When is_ignored is true, linenum_of_matching_rule will be the line
+	// number of the rule causing relpath to be ignored and pattern is the
+	// textual representation of the matching pattern.
+	IsIgnored(relpath string, ftype fs.FileMode) (is_ignored bool, linenum_of_matching_rule int, pattern string)
+}
+
+func NewGitignore() IgnoreFile { return &Gitignore{index_of_last_negated_rule: -1} }

tools/ignorefiles/gitignore.go

@@ -2,29 +2,112 @@ package ignorefiles
 
 import (
 	"fmt"
+	"io"
 	"io/fs"
 	"os"
 	"path/filepath"
 	"slices"
 	"strings"
+
+	"github.com/kovidgoyal/kitty/tools/utils"
 )
 
 var _ = fmt.Print
 
 type GitPattern struct {
-	only_dirs bool
-	negated   bool
-	parts     []string
-	matcher   func(path string) bool
+	line_number int
+	only_dirs   bool
+	negated     bool
+	pattern     string
+	parts       []string
+	matcher     func(path string) bool
+}
+
+type Gitignore struct {
+	patterns                   []GitPattern
+	index_of_last_negated_rule int
+	line_number_offset         int
+}
+
+func (g Gitignore) IsIgnored(relpath string, ftype os.FileMode) (is_ignored bool, linenum_of_matching_rule int, pattern string) {
+	if os.PathSeparator != '/' {
+		relpath = strings.ReplaceAll(relpath, string(os.PathSeparator), "/")
+	}
+	linenum_of_matching_rule = -1
+	for i, pat := range g.patterns {
+		if is_ignored {
+			if i > g.index_of_last_negated_rule {
+				break
+			}
+			if pat.negated && pat.Match(relpath, ftype) {
+				is_ignored = false
+				linenum_of_matching_rule = -1
+				pattern = ""
+			}
+		} else {
+			if !pat.negated && pat.Match(relpath, ftype) {
+				is_ignored = true
+				linenum_of_matching_rule = pat.line_number
+				pattern = pat.pattern
+			}
+		}
+	}
+	return
+}
+
+func (g *Gitignore) load_line(line string, line_number int) {
+	if p, skipped_line := CompileGitIgnoreLine(line); !skipped_line {
+		p.line_number = g.line_number_offset + line_number
+		g.patterns = append(g.patterns, p)
+		if p.negated {
+			g.index_of_last_negated_rule = len(g.patterns) - 1
+		}
+	}
+}
+
+func (g *Gitignore) LoadLines(lines ...string) error {
+	for i, line := range lines {
+		g.load_line(line, i)
+	}
+	g.line_number_offset += len(lines)
+	return nil
+}
+
+func (g *Gitignore) LoadString(text string) error {
+	s := utils.NewLineScanner(text)
+	lnum := 0
+	for s.Scan() {
+		g.load_line(s.Text(), lnum)
+		lnum++
+	}
+	g.line_number_offset += lnum
+	return nil
+}
+
+func (g *Gitignore) LoadBytes(text []byte) error {
+	return g.LoadString(string(text))
+}
+
+func (g *Gitignore) LoadPath(path string) error {
+	if data, err := os.ReadFile(path); err == nil {
+		return g.LoadString(utils.UnsafeBytesToString(data))
+	} else {
+		return err
+	}
+}
+
+func (g *Gitignore) LoadFile(f io.Reader) error {
+	if data, err := io.ReadAll(f); err == nil {
+		return g.LoadString(utils.UnsafeBytesToString(data))
+	} else {
+		return err
+	}
 }
 
 func (p GitPattern) Match(path string, ftype fs.FileMode) bool {
 	if p.only_dirs && ftype&fs.ModeDir == 0 {
 		return false
 	}
-	if os.PathSeparator != '/' {
-		path = strings.ReplaceAll(path, string(os.PathSeparator), "/")
-	}
 	return p.matcher(path)
 }
 
@@ -122,6 +205,7 @@ func CompileGitIgnoreLine(line string) (ans GitPattern, skipped_line bool) {
 		skipped_line = true
 		return
 	}
+	ans.pattern = line
 
 	// Handle negated (accept) patterns
 	if line[0] == '!' {

tools/ignorefiles/gitignore_test.go

@@ -98,4 +98,48 @@ func TestGitignore(t *testing.T) {
 			}
 		}
 	}
+	for text, tests := range map[string]map[string]bool{
+		``: {"foo": false},
+		`
+# exclude everything except directory foo/bar
+/*
+!/foo
+/foo/*
+!/foo/bar`: {
+			"a": true, "foo": false, "foo/x": true, "foo/bar": false, "foo/bar/": false,
+		},
+		`
+**/foo
+bar `: {
+			"foo": true, "baz/foo": true, "bar": true, "baz/bar": true, "a": false,
+		},
+		`/*.c`: {"a.c": true, "b/a.c": false},
+		`
+**/external/**/*.json
+**/external/**/.*ignore
+**/external/foobar/*.css`: {
+			"external/foobar/angular.foo.css": true, "external/barfoo/.gitignore": true, "external/barfoo/.bower.json": true,
+		},
+		"abc/def\r\nxyz": {"abc/def": true, "a/xyz": true},
+		`/**/foo`:        {"foo": true, "foo/": true, "a/b/foo": true, "fooo": false, "ofoo": false},
+		"/.js":           {".js": true, ".js/": true, ".js/a": true, ".jsa": false},
+		"*.js":           {".js": true, ".js/": true, ".js/a": true, "a.js/a": true, "a.js/a.js": true, ".jsa": false, "a.jsa": false},
+		"foo/**/":        {"foo/": false, "foo": false, "foo/abc/": true, "foo/a/b/c/": true, "foo/a": false},
+		"foo/**/*.bar":   {"foo/": false, "abc.bar": false, "foo/abc.bar": true, "foo/a.bar/": true, "foo/x/y/z.bar": true},
+		`\#abc`:          {"abc": false, "#abc": true},
+		"abc\n!abc/x":    {"abc": true, "abc/x": false, "abc/y": true},
+		`abc/*`:          {"abc": false, "abc/": false, "abc/x": true},
+	} {
+		p := NewGitignore()
+		if err := p.LoadString(text); err != nil {
+			t.Fatal(err)
+		}
+		for tpath, expected := range tests {
+			path := strings.TrimRight(tpath, "/")
+			ftype := utils.IfElse(len(path) < len(tpath), fs.ModeDir, 0)
+			if actual, _, _ := p.IsIgnored(path, ftype); actual != expected {
+				t.Fatalf("ignored: %v != %v for path: %#v and ignorefile:\n%s", expected, actual, tpath, text)
+			}
+		}
+	}
 }