ci: add typechecking, fail fast in CI, and patch typechecking errors (#63)

src/tools/impl/Grep.ts

@@ -113,7 +113,9 @@ export async function grep(args: GrepArgs): Promise<GrepResult> {
       for (const line of lines) {
         const parts = line.split(":");
         if (parts.length >= 2) {
-          const count = parseInt(parts[parts.length - 1], 10);
+          const lastPart = parts[parts.length - 1];
+          if (!lastPart) continue;
+          const count = parseInt(lastPart, 10);
           if (!Number.isNaN(count) && count > 0) {
             totalMatches += count;
             filesWithMatches++;

src/tools/impl/LS.ts

@@ -19,7 +19,11 @@ export async function ls(
   args: LSArgs,
 ): Promise<{ content: Array<{ type: string; text: string }> }> {
   validateRequiredParams(args, ["path"], "LS");
-  validateParamTypes(args, LSSchema, "LS");
+  validateParamTypes(
+    args as unknown as Record<string, unknown>,
+    LSSchema,
+    "LS",
+  );
   const { path: inputPath, ignore = [] } = args;
   const dirPath = resolve(inputPath);
   try {

src/tools/impl/MultiEdit.ts

@@ -25,12 +25,16 @@ export async function multi_edit(
     throw new Error(`File path must be absolute, got: ${file_path}`);
   if (!edits || edits.length === 0) throw new Error("No edits provided");
   for (let i = 0; i < edits.length; i++) {
+    const edit = edits[i];
+    if (!edit) {
+      throw new Error(`Edit ${i + 1} is undefined`);
+    }
     validateRequiredParams(
-      edits[i] as Record<string, unknown>,
+      edit as unknown as Record<string, unknown>,
       ["old_string", "new_string"],
       `MultiEdit (edit ${i + 1})`,
     );
-    if (edits[i].old_string === edits[i].new_string)
+    if (edit.old_string === edit.new_string)
       throw new Error(
         `Edit ${i + 1}: No changes to make: old_string and new_string are exactly the same.`,
       );
@@ -39,7 +43,9 @@ export async function multi_edit(
     let content = await fs.readFile(file_path, "utf-8");
     const appliedEdits: string[] = [];
     for (let i = 0; i < edits.length; i++) {
-      const { old_string, new_string, replace_all = false } = edits[i];
+      const edit = edits[i];
+      if (!edit) continue;
+      const { old_string, new_string, replace_all = false } = edit;
       const occurrences = content.split(old_string).length - 1;
       if (occurrences === 0) {
         throw new Error(