feat(motion): add % motion

Author: suveshmoza

src/glide/browser/actors/GlideHandlerChild.sys.mts

@@ -567,6 +567,10 @@ export class GlideHandlerChild extends JSWindowActorChild<
             motions.end_of_line(editor, false);
             break;
           }
+          case "%": {
+            motions.jump_to_matching_bracket(editor);
+            break;
+          }
           case "s": {
             // caret is on the first line and it's empty
             if (motions.is_bof(editor) && motions.next_char(editor) === "\n") {
@@ -701,6 +705,7 @@ export class GlideHandlerChild extends JSWindowActorChild<
       case "b":
       case "B":
       case "$":
+      case "%":
       case "{":
       case "}":
       case "s":

src/glide/browser/base/content/browser-excmds-registry.mts

@@ -444,6 +444,7 @@ export const GLIDE_EXCOMMANDS = [
             "0",
             "^",
             "$",
+            "%",
             "{",
             "}",
             "s",

src/glide/browser/base/content/motions.mts

@@ -8,6 +8,7 @@ import type { GlideOperator } from "./browser-excmds-registry.mts";
 const text_obj = ChromeUtils.importESModule("chrome://glide/content/text-objects.mjs");
 const { assert_never } = ChromeUtils.importESModule("chrome://glide/content/utils/guards.mjs");
 const strings = ChromeUtils.importESModule("chrome://glide/content/utils/strings.mjs");
+const { is_text_field } = ChromeUtils.importESModule("chrome://glide/content/utils/dom.mjs");
 
 /**
  * A minimal representation of `nsIEditor` so that we can re-implement editors
@@ -529,6 +530,37 @@ export function first_non_whitespace(editor: Editor, extend: boolean = false) {
   }
 }
 
+export function jump_to_matching_bracket(editor: nsIEditor): void {
+  const root = editor.rootElement;
+
+  if (is_text_field(root)) {
+    const start = root.selectionStart;
+    if (start == null) {
+      return;
+    }
+    const new_offset = strings.jump_to_matching_bracket_offset(root.value, start);
+    if (new_offset === null) {
+      return;
+    }
+    root.setSelectionRange(new_offset, new_offset);
+    return;
+  }
+
+  const node = editor.selection.focusNode;
+  if (node?.nodeType !== Node.TEXT_NODE) {
+    return;
+  }
+  const text = node.textContent;
+  if (text == null) {
+    return;
+  }
+  const new_offset = strings.jump_to_matching_bracket_offset(text, editor.selection.focusOffset);
+  if (new_offset === null) {
+    return;
+  }
+  editor.selection.collapse(node, new_offset);
+}
+
 /**
  * Delete the current selection range.
  */

src/glide/browser/base/content/plugins/keymaps.mts

@@ -110,6 +110,7 @@ export function init(sandbox: Sandbox) {
   glide.keymaps.set("normal", "0", "motion 0");
   glide.keymaps.set("normal", "^", "motion ^");
   glide.keymaps.set("normal", "$", "motion $");
+  glide.keymaps.set("normal", "%", "motion %");
   glide.keymaps.set("normal", "h", "caret_move left");
   glide.keymaps.set("normal", "l", "caret_move right");
   glide.keymaps.set("normal", "j", "caret_move down");

src/glide/browser/base/content/test/motions/browser_normal_motions.ts

@@ -501,3 +501,52 @@ add_task(async function test_normal_caret() {
     await test_motion("^", 2, "h");
   });
 });
+
+add_task(async function test_normal_percent() {
+  await BrowserTestUtils.withNewTab(INPUT_TEST_FILE, async browser => {
+    const { set_text, test_motion, set_selection } = GlideTestUtils.make_input_test_helpers(browser, { text_start: 1 });
+
+    await set_text("a(b)c", "open paren to close");
+    await set_selection(1, "(");
+    await test_motion("%", 3, ")");
+
+    await set_text("a(b)c", "close paren to open");
+    await set_selection(3, ")");
+    await test_motion("%", 1, "(");
+
+    await set_text("((x))", "nested parens from outer open");
+    await set_selection(0, "(");
+    await test_motion("%", 4, ")");
+
+    await set_text("((x))", "nested parens from inner open");
+    await set_selection(1, "(");
+    await test_motion("%", 3, ")");
+
+    await set_text("((x))", "nested parens from final close");
+    await set_selection(4, ")");
+    await test_motion("%", 0, "(");
+
+    await set_text("[a]", "square brackets");
+    await set_selection(0, "[");
+    await test_motion("%", 2, "]");
+
+    await set_text("{a}", "curly brackets");
+    await set_selection(0, "{");
+    await test_motion("%", 2, "}");
+
+    await set_text("(\n)", "multiline pair");
+    await set_selection(0, "(");
+    await test_motion("%", 2, ")");
+
+    await set_text("a (b)", "text before open paren, jump to close");
+    await set_selection(0, "a");
+    await test_motion("%", 4, ")");
+
+    await set_text("abc", "no bracket on rest of line");
+    await test_motion("%", 0, "a");
+
+    await set_text("abc(de", "unbalanced bracket on line");
+    await set_selection(3, "(");
+    await test_motion("%", 3, "(");
+  });
+});

src/glide/browser/base/content/utils/dom.mts

@@ -334,3 +334,22 @@ export function in_frames(window: Window, n: number, func: () => void): void {
 
   window.requestAnimationFrame(wait);
 }
+
+export function is_text_field(el: Element): el is HTMLTextAreaElement | HTMLInputElement {
+  if (el instanceof HTMLTextAreaElement) {
+    return true;
+  }
+  if (el instanceof HTMLInputElement) {
+    const t = el.type;
+    return (
+      t === "text"
+      || t === "search"
+      || t === "url"
+      || t === "tel"
+      || t === "password"
+      || t === "email"
+      || t === ""
+    );
+  }
+  return false;
+}

src/glide/browser/base/content/utils/strings.mts

@@ -274,3 +274,89 @@ export function decode_utf8(bytes: Uint8Array) {
       ?? ((decoder = new (globalThis as any).TextDecoder()), (decode_utf8_ = decoder.decode.bind(decoder)))
   )(bytes);
 }
+
+const BRACKET_OPEN_TO_CLOSE: Record<string, string> = {
+  "(": ")",
+  "[": "]",
+  "{": "}",
+};
+const BRACKET_CLOSE_TO_OPEN: Record<string, string> = {
+  ")": "(",
+  "]": "[",
+  "}": "{",
+};
+
+export function is_bracket_char(c: string): boolean {
+  return c in BRACKET_OPEN_TO_CLOSE || c in BRACKET_CLOSE_TO_OPEN;
+}
+
+export function find_matching_bracket_index(text: string, start_idx: number): number | null {
+  const ch = text[start_idx]!;
+  const open = BRACKET_CLOSE_TO_OPEN[ch];
+  if (open !== undefined) {
+    const close = ch;
+    let depth = 0;
+    for (let i = start_idx; i >= 0; i--) {
+      const c = text[i]!;
+      if (c === close) {
+        depth++;
+      } else if (c === open) {
+        depth--;
+        if (depth === 0) {
+          return i;
+        }
+      }
+    }
+    return null;
+  }
+
+  const close = BRACKET_OPEN_TO_CLOSE[ch];
+  if (close !== undefined) {
+    const open = ch;
+    let depth = 0;
+    for (let i = start_idx; i < text.length; i++) {
+      const c = text[i]!;
+      if (c === open) {
+        depth++;
+      } else if (c === close) {
+        depth--;
+        if (depth === 0) {
+          return i;
+        }
+      }
+    }
+    return null;
+  }
+
+  return null;
+}
+
+export function jump_to_matching_bracket_offset(text: string, focus_offset: number): number | null {
+  const index_left_of_caret = focus_offset >= 1 ? focus_offset - 1 : -1;
+
+  const next_newline_index = text.indexOf("\n", Math.max(0, index_left_of_caret));
+  const line_end_exclusive = next_newline_index === -1 ? text.length : next_newline_index;
+
+  let bracket_index: number | null = null;
+  if (index_left_of_caret >= 0 && is_bracket_char(text[index_left_of_caret]!)) {
+    bracket_index = index_left_of_caret;
+  } else {
+    const scan_start = index_left_of_caret < 0 ? 0 : index_left_of_caret + 1;
+    for (let i = scan_start; i < line_end_exclusive; i++) {
+      if (is_bracket_char(text[i]!)) {
+        bracket_index = i;
+        break;
+      }
+    }
+  }
+
+  if (bracket_index === null) {
+    return null;
+  }
+
+  const matching_bracket_index = find_matching_bracket_index(text, bracket_index);
+  if (matching_bracket_index === null) {
+    return null;
+  }
+  return matching_bracket_index + 1;
+}