Add regression tests for hyphen word motions (#156)

Change-Id: Ic9119dc0b38a8208622ecb8a5c028775aca5a1da
Signed-off-by: Thomas Kosiewski <tk@coder.com>

---------

Signed-off-by: Thomas Kosiewski <tk@coder.com>

Author: ThomasK33

src/utils/vim.test.ts

@@ -133,6 +133,69 @@ describe("Vim Command Integration Tests", () => {
     });
   });
 
+  describe("Navigation", () => {
+    test("w moves to next word", () => {
+      const state = executeVimCommands(
+        { ...initialState, text: "hello world foo", cursor: 0, mode: "normal" },
+        ["w"]
+      );
+      expect(state.cursor).toBe(6);
+    });
+
+    test("b moves to previous word", () => {
+      const state = executeVimCommands(
+        { ...initialState, text: "hello world foo", cursor: 12, mode: "normal" },
+        ["b"]
+      );
+      expect(state.cursor).toBe(6);
+    });
+
+    test("$ moves to end of line", () => {
+      const state = executeVimCommands(
+        { ...initialState, text: "hello world", cursor: 0, mode: "normal" },
+        ["$"]
+      );
+      expect(state.cursor).toBe(10); // On last char, not past it
+    });
+
+    test("0 moves to start of line", () => {
+      const state = executeVimCommands(
+        { ...initialState, text: "hello world", cursor: 10, mode: "normal" },
+        ["0"]
+      );
+      expect(state.cursor).toBe(0);
+    });
+
+    test("w skips punctuation separators like hyphen", () => {
+      const initial = {
+        ...initialState,
+        text: "asd-f asdf asdf",
+        cursor: 0,
+        mode: "normal" as const,
+      };
+
+      const afterFirstW = executeVimCommands(initial, ["w"]);
+      expect(afterFirstW.cursor).toBe(4);
+
+      const afterSecondW = executeVimCommands(afterFirstW, ["w"]);
+      expect(afterSecondW.cursor).toBe(6);
+    });
+
+    test("e moves past punctuation to end of next word", () => {
+      const state = executeVimCommands(
+        {
+          ...initialState,
+          text: "asd-f asdf asdf",
+          cursor: 3,
+          mode: "normal",
+        },
+        ["e"]
+      );
+
+      expect(state.cursor).toBe(4);
+    });
+  });
+
   describe("Simple Edits", () => {
     test("x deletes character under cursor", () => {
       const state = executeVimCommands(

src/utils/vim.ts

@@ -128,12 +128,35 @@ export function moveVertical(
  * In normal mode, cursor should never go past the last character.
  */
 export function moveWordForward(text: string, cursor: number): number {
-  let i = cursor;
   const n = text.length;
-  while (i < n && /[A-Za-z0-9_]/.test(text[i])) i++;
-  while (i < n && /\s/.test(text[i])) i++;
-  // Clamp to last character position in normal mode (never past the end)
-  return Math.min(i, Math.max(0, n - 1));
+  if (n === 0) return 0;
+
+  let i = Math.max(0, Math.min(cursor, n - 1));
+  const isWord = (ch: string) => /[A-Za-z0-9_]/.test(ch);
+
+  const advancePastWord = (idx: number): number => {
+    let j = idx;
+    while (j < n && isWord(text[j])) j++;
+    return j;
+  };
+
+  const advanceToWord = (idx: number): number => {
+    let j = idx;
+    while (j < n && !isWord(text[j])) j++;
+    return j;
+  };
+
+  if (isWord(text[i])) {
+    i = advancePastWord(i);
+  }
+
+  i = advanceToWord(i);
+
+  if (i >= n) {
+    return Math.max(0, n - 1);
+  }
+
+  return i;
 }
 
 /**
@@ -144,32 +167,34 @@ export function moveWordForward(text: string, cursor: number): number {
  */
 export function moveWordEnd(text: string, cursor: number): number {
   const n = text.length;
+  if (n === 0) return 0;
   if (cursor >= n - 1) return Math.max(0, n - 1);
 
-  let i = cursor;
+  const clamp = Math.max(0, Math.min(cursor, n - 1));
   const isWord = (ch: string) => /[A-Za-z0-9_]/.test(ch);
 
-  // If on a word char, check if we're at the end of it
-  if (isWord(text[i])) {
-    // If next char is not a word char, we're at the end - move to next word
-    if (i < n - 1 && !isWord(text[i + 1])) {
-      // Skip whitespace to find next word
-      i++;
-      while (i < n - 1 && !isWord(text[i])) i++;
-      // Move to end of next word
-      while (i < n - 1 && isWord(text[i + 1])) i++;
-      return i;
-    }
-    // Not at end yet, move to end of current word
+  if (!isWord(text[clamp])) {
+    let i = clamp;
+    while (i < n && !isWord(text[i])) i++;
+    if (i >= n) return Math.max(0, n - 1);
     while (i < n - 1 && isWord(text[i + 1])) i++;
     return i;
   }
 
-  // If on whitespace, skip to next word then go to its end
-  while (i < n - 1 && !isWord(text[i])) i++;
-  while (i < n - 1 && isWord(text[i + 1])) i++;
+  let endOfCurrent = clamp;
+  while (endOfCurrent < n - 1 && isWord(text[endOfCurrent + 1])) endOfCurrent++;
+
+  if (clamp < endOfCurrent) {
+    return endOfCurrent;
+  }
+
+  let j = endOfCurrent + 1;
+  while (j < n && !isWord(text[j])) j++;
+  if (j >= n) return Math.max(0, n - 1);
 
-  return Math.min(i, Math.max(0, n - 1));
+  let endOfNext = j;
+  while (endOfNext < n - 1 && isWord(text[endOfNext + 1])) endOfNext++;
+  return endOfNext;
 }
 
 /**