keybinds(niri): add preprocessors to KDL parsing

fixes #2230

core/internal/keybinds/providers/niri.go

@@ -10,7 +10,6 @@ import (
 	"strings"
 
 	"github.com/AvengeMedia/DankMaterialShell/core/internal/keybinds"
-	"github.com/sblinch/kdl-go"
 	"github.com/sblinch/kdl-go/document"
 )
 
@@ -292,7 +291,7 @@ func (n *NiriProvider) loadOverrideBinds() (map[string]*overrideBind, error) {
 	parser := NewNiriParser(filepath.Dir(overridePath))
 	parser.currentSource = overridePath
 
-	doc, err := kdl.Parse(strings.NewReader(string(data)))
+	doc, err := parseKDL(data)
 	if err != nil {
 		return nil, err
 	}

core/internal/keybinds/providers/niri_parser.go

@@ -50,6 +50,103 @@ type NiriParser struct {
 	conflictingConfigs map[string]*NiriKeyBinding
 }
 
+func parseKDL(data []byte) (*document.Document, error) {
+	return kdl.Parse(strings.NewReader(normalizeKDLBraces(string(data))))
+}
+
+func normalizeKDLBraces(input string) string {
+	var sb strings.Builder
+	sb.Grow(len(input))
+
+	var prev byte
+	n := len(input)
+	for i := 0; i < n; {
+		c := input[i]
+
+		switch {
+		case c == '"':
+			end := findStringEnd(input, i)
+			sb.WriteString(input[i:end])
+			prev = '"'
+			i = end
+		case c == '/' && i+1 < n && input[i+1] == '/':
+			end := findLineCommentEnd(input, i)
+			sb.WriteString(input[i:end])
+			prev = '\n'
+			i = end
+		case c == '/' && i+1 < n && input[i+1] == '*':
+			end := findBlockCommentEnd(input, i)
+			sb.WriteString(input[i:end])
+			prev = '/'
+			i = end
+		case c == '{' && prev != 0 && !isBraceAdjacentSpace(prev):
+			sb.WriteByte(' ')
+			sb.WriteByte(c)
+			prev = c
+			i++
+		default:
+			sb.WriteByte(c)
+			prev = c
+			i++
+		}
+	}
+
+	return sb.String()
+}
+
+func findStringEnd(s string, start int) int {
+	n := len(s)
+	for i := start + 1; i < n; {
+		switch s[i] {
+		case '\\':
+			i += 2
+		case '"':
+			return i + 1
+		default:
+			i++
+		}
+	}
+	return n
+}
+
+func findLineCommentEnd(s string, start int) int {
+	for i := start + 2; i < len(s); i++ {
+		if s[i] == '\n' {
+			return i
+		}
+	}
+	return len(s)
+}
+
+func findBlockCommentEnd(s string, start int) int {
+	n := len(s)
+	depth := 1
+	for i := start + 2; i < n && depth > 0; {
+		switch {
+		case i+1 < n && s[i] == '/' && s[i+1] == '*':
+			depth++
+			i += 2
+		case i+1 < n && s[i] == '*' && s[i+1] == '/':
+			depth--
+			i += 2
+			if depth == 0 {
+				return i
+			}
+		default:
+			i++
+		}
+	}
+	return n
+}
+
+func isBraceAdjacentSpace(b byte) bool {
+	switch b {
+	case ' ', '\t', '\n', '\r', '{':
+		return true
+	}
+	return false
+}
+
 func NewNiriParser(configDir string) *NiriParser {
 	return &NiriParser{
 		configDir:          configDir,
@@ -91,7 +188,7 @@ func (p *NiriParser) parseDMSBindsDirectly(dmsBindsPath string, section *NiriSec
 		return
 	}
 
-	doc, err := kdl.Parse(strings.NewReader(string(data)))
+	doc, err := parseKDL(data)
 	if err != nil {
 		return
 	}
@@ -159,7 +256,7 @@ func (p *NiriParser) parseFile(filePath, sectionName string) (*NiriSection, erro
 		return nil, fmt.Errorf("failed to read %s: %w", absPath, err)
 	}
 
-	doc, err := kdl.Parse(strings.NewReader(string(data)))
+	doc, err := parseKDL(data)
 	if err != nil {
 		return nil, fmt.Errorf("failed to parse KDL in %s: %w", absPath, err)
 	}

core/internal/keybinds/providers/niri_parser_test.go

@@ -3,9 +3,74 @@ package providers
 import (
 	"os"
 	"path/filepath"
+	"slices"
 	"testing"
 )
 
+func TestNiriParse_NoSpaceBeforeBrace(t *testing.T) {
+	config := `recent-windows {
+    binds {
+        Alt+Tab         { next-window scope="output"; }
+        Alt+Shift+Tab   { previous-window scope="output"; }
+        Alt+grave       { next-window filter="app-id"; }
+        Alt+Shift+grave { previous-window filter="app-id"; }
+        Alt+Escape      { next-window scope="all"; }
+        Alt+Shift+Escape{ previous-window scope="all"; }
+    }
+}
+`
+	tmpDir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(tmpDir, "config.kdl"), []byte(config), 0o644); err != nil {
+		t.Fatalf("Failed to write test config: %v", err)
+	}
+
+	result, err := ParseNiriKeys(tmpDir)
+	if err != nil {
+		t.Fatalf("ParseNiriKeys failed on valid niri config: %v", err)
+	}
+
+	var found *NiriKeyBinding
+	for i := range result.Section.Keybinds {
+		kb := &result.Section.Keybinds[i]
+		if kb.Key == "Escape" && slices.Contains(kb.Mods, "Alt") && slices.Contains(kb.Mods, "Shift") {
+			found = kb
+			break
+		}
+	}
+	if found == nil {
+		t.Fatal("Alt+Shift+Escape bind missing — '{' without preceding space was not handled")
+	}
+	if found.Action != "previous-window" {
+		t.Errorf("Action = %q, want %q", found.Action, "previous-window")
+	}
+}
+
+func TestNormalizeKDLBraces(t *testing.T) {
+	tests := []struct {
+		name string
+		in   string
+		out  string
+	}{
+		{"already spaced", "node { child }\n", "node { child }\n"},
+		{"missing space", "node{ child }\n", "node { child }\n"},
+		{"niri keybind", "Alt+Shift+Escape{ previous-window; }", "Alt+Shift+Escape { previous-window; }"},
+		{"brace inside string", `node "a{b" { child }`, `node "a{b" { child }`},
+		{"brace in line comment", "// foo{bar\nnode { }", "// foo{bar\nnode { }"},
+		{"brace in block comment", "/* foo{bar */ node{ }", "/* foo{bar */ node { }"},
+		{"escaped quote in string", `node "a\"b{c" { }`, `node "a\"b{c" { }`},
+		{"leading brace", "{ child }", "{ child }"},
+		{"nested missing space", "a{b{ c }}", "a {b { c }}"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := normalizeKDLBraces(tc.in)
+			if got != tc.out {
+				t.Errorf("normalizeKDLBraces(%q) = %q, want %q", tc.in, got, tc.out)
+			}
+		})
+	}
+}
+
 func TestNiriParseKeyCombo(t *testing.T) {
 	tests := []struct {
 		combo        string