Fix toplevel async stuff

Author: tmr232

src/file-parsing/vite.ts

@@ -4,14 +4,23 @@ import { initializeParser } from "../parser-loader/vite.ts";
 import { makeIterFunctions } from "./file-parsing.ts";
 export { getLanguage, fileTypes } from "./file-parsing.ts";
 
-const parsers: { [language in Language]: Parser } = Object.fromEntries(
-  await (async () => {
-    const parsers = [];
-    for (const language of supportedLanguages) {
-      parsers.push([language, await initializeParser(language)]);
-    }
-    return parsers;
-  })(),
-);
+let parsers: { [language in Language]: Parser }|undefined;
+export async function initParsers() {
+  if (parsers) return;
+  parsers = Object.fromEntries(
+    await (async () => {
+      const parsers = [];
+      for (const language of supportedLanguages) {
+        parsers.push([language, await initializeParser(language)]);
+      }
+      return parsers;
+    })(),
+  );
+}
 
-export const iterFunctions = makeIterFunctions(parsers);
+export function iterFunctions(code: string, language: Language) : IterableIterator<Parser.SyntaxNode> {
+  if (!parsers) {
+    throw new Error("Must initialize parsers by calling `initParsers()`");
+  }
+  return makeIterFunctions(parsers)(code, language);
+}

src/render/src/App.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { getLanguage, iterFunctions } from "../../file-parsing/vite";
+  import { getLanguage, initParsers, iterFunctions } from "../../file-parsing/vite";
   import type Parser from "web-tree-sitter";
   import { type SyntaxNode } from "web-tree-sitter";
   import { type Language, newCFGBuilder } from "../../control-flow/cfg";
@@ -71,11 +71,12 @@
    * @param language Source code language
    * @param line Line number, 1-based.
    */
-  function getFunctionByLine(
+  async function getFunctionByLine(
     code: string,
     language: Language,
     line: number,
-  ): SyntaxNode | undefined {
+  ): Promise<SyntaxNode | undefined> {
+    await initParsers();
     for (const func of iterFunctions(code, language)) {
       // GitHub lines are 1-based, TreeSitter rows are 0-based
       if (func.startPosition.row + 1 === line) {
@@ -117,7 +118,7 @@
     // We assume that the raw URL always ends with the file extension
     const language = getLanguage(rawURL);
 
-    const func = getFunctionByLine(code, language, line);
+    const func = await getFunctionByLine(code, language, line);
     if (!func) {
       throw new Error(`Unable to find function on line ${line}`);
     }