wasm: Fix infinite loop in Node.text when tree and text are out-of-sync

lib/binding_web/binding.js

@@ -67,7 +67,7 @@ class Parser {
 
   parse(callback, oldTree, options) {
     if (typeof callback === 'string') {
-      currentParseCallback = index => callback.slice(index);
+      currentParseCallback = (index, _, endIndex) => callback.slice(index, endIndex);
     } else if (typeof callback === 'function') {
       currentParseCallback = callback;
     } else {
@@ -243,13 +243,23 @@ class Node {
   }
 
   get text() {
-    const startIndex = this.startIndex;
-    const length = this.endIndex - startIndex;
-    let result = this.tree.textCallback(startIndex);
-    while (result.length < length) {
-      result += this.tree.textCallback(startIndex + result.length);
+    let {startIndex, endIndex} = this;
+    const length = endIndex - startIndex;
+    let result = this.tree.textCallback(startIndex, null, endIndex);
+    startIndex += result.length;
+    while (startIndex < endIndex) {
+      const string = this.tree.textCallback(startIndex, null, endIndex);
+      if (string && string.length > 0) {
+        startIndex += string.length;
+        result += string;
+      } else {
+        break;
+      }
     }
-    return result.slice(0, length);
+    if (startIndex > endIndex) {
+      result = result.slice(0, length);
+    }
+    return result;
   }
 
   isNamed() {

lib/binding_web/tree-sitter-web.d.ts

@@ -35,10 +35,11 @@ declare module 'web-tree-sitter' {
       type: "parse" | "lex"
     ) => void;
 
-    export interface Input {
-      seek(index: number): void;
-      read(): any;
-    }
+    export type Input = (
+      startIndex: number,
+      startPoint?: Point,
+      endIndex?: number,
+    ) => string | null;
 
     export interface SyntaxNode {
       tree: Tree;