Fixing delay caused in vscode due to pasteEdits

src/services/pasteEdits.ts

@@ -3,12 +3,15 @@ import {
     codefix,
     Debug,
     fileShouldUseJavaScriptRequire,
+    findAncestor,
     findIndex,
     forEachChild,
     formatting,
     getQuotePreference,
+    getTokenAtPosition,
     isIdentifier,
     Program,
+    rangeContainsPosition,
     SourceFile,
     Statement,
     SymbolFlags,
@@ -62,7 +65,6 @@ function pasteEdits(
     }
 
     const statements: Statement[] = [];
-
     let newText = targetFile.text;
     for (let i = pasteLocations.length - 1; i >= 0; i--) {
         const { pos, end } = pasteLocations[i];
@@ -104,12 +106,33 @@ function pasteEdits(
                 preferences,
                 formatContext,
             };
-            forEachChild(updatedFile, function cb(node) {
-                if (isIdentifier(node) && !originalProgram?.getTypeChecker().resolveName(node.text, node, SymbolFlags.All, /*excludeGlobals*/ false)) {
-                    // generate imports
-                    importAdder.addImportForUnresolvedIdentifier(context, node, /*useAutoImportProvider*/ true);
-                }
-                node.forEachChild(cb);
+
+            // `updatedRanges` represent the new ranges that account for the offset changes caused by pasting new text and
+            // `offset` represents by how much the starting position of `pasteLocations` needs to be changed.
+            //
+            // We iterate over each updated range to get the node that wholly encloses the updated range. For each child of that node, it is checked if the
+            // identifier lies within the updated range and if it is not resolved, we try resolving it.
+
+            const updatedRanges: TextRange[] = [];
+            let offset = 0;
+            pasteLocations.forEach((location, i) => {
+                const deletionNeeded = location.pos === location.end ? 0 : location.end - location.pos;
+                const textToBePasted = actualPastedText ? actualPastedText[0] : pastedText[i];
+                const startPos = location.pos - offset;
+                const endPos = startPos + textToBePasted.length;
+                updatedRanges.push({ pos: startPos, end: endPos });
+                offset += deletionNeeded - textToBePasted.length;
+            });
+
+            updatedRanges.forEach(range => {
+                const enclosingNode = findAncestor(getTokenAtPosition(context.sourceFile, range.pos), ancestorNode => rangeContainsPosition(ancestorNode, range.end));
+                if (!enclosingNode) return;
+                forEachChild(enclosingNode, function cb(node) {
+                    if (isIdentifier(node) && rangeContainsPosition(range, node.getStart(updatedFile)) && !originalProgram?.getTypeChecker().resolveName(node.text, node, SymbolFlags.All, /*excludeGlobals*/ false)) {
+                        importAdder.addImportForUnresolvedIdentifier(context, node, /*useAutoImportProvider*/ true);
+                    }
+                    node.forEachChild(cb);
+                });
             });
         }
         importAdder.writeFixes(changes, getQuotePreference(copiedFrom ? copiedFrom.file : targetFile, preferences));