Implementing copy/paste

src/harness/client.ts

@@ -48,6 +48,8 @@ import {
     notImplemented,
     OrganizeImportsArgs,
     OutliningSpan,
+    PasteEdits,
+    PasteEditsArgs,
     PatternMatchKind,
     Program,
     QuickInfo,
@@ -1006,6 +1008,25 @@ export class SessionClient implements LanguageService {
         return getSupportedCodeFixes();
     }
 
+    getPasteEdits(
+        { targetFile, pastedText, pasteLocations, copiedFrom }: PasteEditsArgs,
+        _formatOptions: FormatCodeSettings,
+    ): PasteEdits {
+        const args: protocol.GetPasteEditsRequestArgs = {
+            file: targetFile,
+            pastedText,
+            pasteLocations: pasteLocations.map(range => ({ start: this.positionToOneBasedLineOffset(targetFile, range.pos), end: this.positionToOneBasedLineOffset(targetFile, range.end) })),
+            copiedFrom: copiedFrom ? { file: copiedFrom.file, range: copiedFrom.range.map(range => ({ start: this.positionToOneBasedLineOffset(copiedFrom.file, range.pos), end: this.positionToOneBasedLineOffset(copiedFrom.file, range.end) })) } : undefined,
+        };
+        const request = this.processRequest<protocol.GetPasteEditsRequest>(protocol.CommandTypes.GetPasteEdits, args);
+        const response = this.processResponse<protocol.GetPasteEditsResponse>(request);
+        if (!response.body) {
+            return { edits: [] };
+        }
+        const edits: FileTextChanges[] = this.convertCodeEditsToTextChanges(response.body.edits);
+        return { edits, fixId: response.body.fixId };
+    }
+
     getProgram(): Program {
         throw new Error("Program objects are not serializable through the server protocol.");
     }

src/harness/fourslashImpl.ts

@@ -3560,6 +3560,11 @@ export class TestState {
         assert.deepEqual(actualModuleSpecifiers, moduleSpecifiers);
     }
 
+    public verifyPasteEdits(options: FourSlashInterface.PasteEditsOptions): void {
+        const editInfo = this.languageService.getPasteEdits({ targetFile: this.activeFile.fileName, pastedText: options.args.pastedText, pasteLocations: options.args.pasteLocations, copiedFrom: options.args.copiedFrom, preferences: options.args.preferences }, this.formatCodeSettings);
+        (options.fixId === editInfo.fixId) ? this.verifyNewContent({ newFileContent: options.newFileContents }, editInfo.edits) : this.raiseError(`Expected to find a fix ${editInfo.fixId}, but none exists`);
+    }
+
     public verifyDocCommentTemplate(expected: ts.TextInsertion | undefined, options?: ts.DocCommentTemplateOptions) {
         const name = "verifyDocCommentTemplate";
         const actual = this.languageService.getDocCommentTemplateAtPosition(this.activeFile.fileName, this.currentCaretPosition, options || { generateReturnInDocTemplate: true }, this.formatCodeSettings)!;

src/harness/fourslashInterfaceImpl.ts

@@ -620,6 +620,10 @@ export class Verify extends VerifyNegatable {
     public organizeImports(newContent: string, mode?: ts.OrganizeImportsMode, preferences?: ts.UserPreferences): void {
         this.state.verifyOrganizeImports(newContent, mode, preferences);
     }
+
+    public pasteEdits(options: PasteEditsOptions): void {
+        this.state.verifyPasteEdits(options);
+    }
 }
 
 export class Edit {
@@ -1923,6 +1927,12 @@ export interface MoveToFileOptions {
     readonly preferences?: ts.UserPreferences;
 }
 
+export interface PasteEditsOptions {
+    readonly newFileContents: { readonly [fileName: string]: string; };
+    args: ts.PasteEditsArgs;
+    readonly fixId: string;
+}
+
 export type RenameLocationsOptions = readonly RenameLocationOptions[] | {
     readonly findInStrings?: boolean;
     readonly findInComments?: boolean;

src/server/project.ts

@@ -2238,6 +2238,18 @@ export abstract class Project implements LanguageServiceHost, ModuleResolutionHo
         return this.noDtsResolutionProject;
     }
 
+    /** @internal */
+    runWithTemporaryFileUpdate(rootFile: string, updatedText: string, cb: (updatedProgram: Program, originalProgram: Program | undefined, updatedFile: SourceFile) => void) {
+        const originalProgram = this.program;
+        const originalText = this.program?.getSourceFile(rootFile)?.getText();
+        Debug.assert(this.program && this.program.getSourceFile(rootFile) && originalText);
+
+        this.getScriptInfo(rootFile)?.editContent(0, this.program.getSourceFile(rootFile)!.getText().length, updatedText);
+        this.updateGraph();
+        cb(this.program, originalProgram, (this.program?.getSourceFile(rootFile))!);
+        this.getScriptInfo(rootFile)?.editContent(0, this.program.getSourceFile(rootFile)!.getText().length, originalText);
+    }
+
     /** @internal */
     private getCompilerOptionsForNoDtsResolutionProject() {
         return {

src/server/protocol.ts

@@ -161,6 +161,7 @@ export const enum CommandTypes {
     GetApplicableRefactors = "getApplicableRefactors",
     GetEditsForRefactor = "getEditsForRefactor",
     GetMoveToRefactoringFileSuggestions = "getMoveToRefactoringFileSuggestions",
+    GetPasteEdits = "getPasteEdits",
     /** @internal */
     GetEditsForRefactorFull = "getEditsForRefactor-full",
 
@@ -625,6 +626,30 @@ export interface GetMoveToRefactoringFileSuggestions extends Response {
     };
 }
 
+/**
+ * Request refactorings at a given position post pasting text from some other location.
+ */
+
+export interface GetPasteEditsRequest extends Request {
+    command: CommandTypes.GetPasteEdits;
+    arguments: GetPasteEditsRequestArgs;
+}
+
+export interface GetPasteEditsRequestArgs extends FileRequestArgs {
+    pastedText: string[];
+    pasteLocations: TextSpan[];
+    copiedFrom?: { file: string; range: TextSpan[]; };
+}
+
+export interface GetPasteEditsResponse extends Response {
+    body: PasteEditsAction;
+}
+
+export interface PasteEditsAction {
+    edits: FileCodeEdits[];
+    fixId?: {};
+}
+
 export interface GetEditsForRefactorRequest extends Request {
     command: CommandTypes.GetEditsForRefactor;
     arguments: GetEditsForRefactorRequestArgs;

src/server/session.ts

@@ -100,6 +100,7 @@ import {
     OperationCanceledException,
     OrganizeImportsMode,
     OutliningSpan,
+    PasteEdits,
     Path,
     perfLogger,
     PerformanceEvent,
@@ -910,6 +911,7 @@ const invalidPartialSemanticModeCommands: readonly protocol.CommandTypes[] = [
     protocol.CommandTypes.PrepareCallHierarchy,
     protocol.CommandTypes.ProvideCallHierarchyIncomingCalls,
     protocol.CommandTypes.ProvideCallHierarchyOutgoingCalls,
+    protocol.CommandTypes.GetPasteEdits,
 ];
 
 const invalidSyntacticModeCommands: readonly protocol.CommandTypes[] = [
@@ -2796,6 +2798,24 @@ export class Session<TMessage = string> implements EventSender {
         return project.getLanguageService().getMoveToRefactoringFileSuggestions(file, this.extractPositionOrRange(args, scriptInfo), this.getPreferences(file));
     }
 
+    private getPasteEdits(args: protocol.GetPasteEditsRequestArgs): protocol.PasteEditsAction | undefined {
+        const { file, project } = this.getFileAndProject(args);
+        const copiedFrom = args.copiedFrom
+            ? { file: args.copiedFrom.file, range: args.copiedFrom.range.map(copies => this.getRange({ file: args.copiedFrom!.file, startLine: copies.start.line, startOffset: copies.start.offset, endLine: copies.end.line, endOffset: copies.end.offset }, project.getScriptInfoForNormalizedPath(toNormalizedPath(args.copiedFrom!.file))!)) }
+            : undefined;
+        const result = project.getLanguageService().getPasteEdits(
+            {
+                targetFile: file,
+                pastedText: args.pastedText,
+                pasteLocations: args.pasteLocations.map(paste => this.getRange({ file, startLine: paste.start.line, startOffset: paste.start.offset, endLine: paste.end.line, endOffset: paste.end.offset }, project.getScriptInfoForNormalizedPath(file)!)),
+                copiedFrom,
+                preferences: this.getPreferences(file),
+            },
+            this.getFormatOptions(file),
+        );
+        return result && this.mapPasteEditsAction(result);
+    }
+
     private organizeImports(args: protocol.OrganizeImportsRequestArgs, simplifiedResult: boolean): readonly protocol.FileCodeEdits[] | readonly FileTextChanges[] {
         Debug.assert(args.scope.type === "file");
         const { file, project } = this.getFileAndProject(args.scope.args);
@@ -2928,6 +2948,10 @@ export class Session<TMessage = string> implements EventSender {
         return { fixName, description, changes: this.mapTextChangesToCodeEdits(changes), commands, fixId, fixAllDescription };
     }
 
+    private mapPasteEditsAction({ edits, fixId }: PasteEdits): protocol.PasteEditsAction {
+        return { edits: this.mapTextChangesToCodeEdits(edits), fixId };
+    }
+
     private mapTextChangesToCodeEdits(textChanges: readonly FileTextChanges[]): protocol.FileCodeEdits[] {
         return textChanges.map(change => this.mapTextChangeToCodeEdit(change));
     }
@@ -3521,6 +3545,9 @@ export class Session<TMessage = string> implements EventSender {
         [protocol.CommandTypes.GetMoveToRefactoringFileSuggestions]: (request: protocol.GetMoveToRefactoringFileSuggestionsRequest) => {
             return this.requiredResponse(this.getMoveToRefactoringFileSuggestions(request.arguments));
         },
+        [protocol.CommandTypes.GetPasteEdits]: (request: protocol.GetPasteEditsRequest) => {
+            return this.requiredResponse(this.getPasteEdits(request.arguments));
+        },
         [protocol.CommandTypes.GetEditsForRefactorFull]: (request: protocol.GetEditsForRefactorRequest) => {
             return this.requiredResponse(this.getEditsForRefactor(request.arguments, /*simplifiedResult*/ false));
         },

src/services/_namespaces/ts.PasteEdits.ts

@@ -0,0 +1 @@
+export * from "../pasteEdits";

src/services/_namespaces/ts.ts

@@ -56,3 +56,5 @@ import * as textChanges from "./ts.textChanges";
 export { textChanges };
 import * as formatting from "./ts.formatting";
 export { formatting };
+import * as pasteEdits from "./ts.PasteEdits";
+export { pasteEdits };

src/services/codefixes/importFixes.ts

@@ -893,10 +893,6 @@ function getSingleExportInfoForSymbol(symbol: Symbol, symbolName: string, module
     }
 }
 
-function isFutureSymbolExportInfoArray(info: readonly SymbolExportInfo[] | readonly FutureSymbolExportInfo[]): info is readonly FutureSymbolExportInfo[] {
-    return info[0].symbol === undefined;
-}
-
 function getImportFixes(
     exportInfos: readonly SymbolExportInfo[] | readonly FutureSymbolExportInfo[],
     usagePosition: number | undefined,
@@ -910,7 +906,7 @@ function getImportFixes(
     fromCacheOnly?: boolean,
 ): { computedWithoutCacheCount: number; fixes: readonly ImportFixWithModuleSpecifier[]; } {
     const checker = program.getTypeChecker();
-    const existingImports = importMap && !isFutureSymbolExportInfoArray(exportInfos) ? flatMap(exportInfos, importMap.getImportsForExportInfo) : emptyArray;
+    const existingImports = importMap ? flatMap(exportInfos, importMap.getImportsForExportInfo) : emptyArray;
     const useNamespace = usagePosition !== undefined && tryUseExistingNamespaceImport(existingImports, usagePosition);
     const addToExisting = tryAddToExistingImport(existingImports, isValidTypeOnlyUseSite, checker, program.getCompilerOptions());
     if (addToExisting) {
@@ -1092,7 +1088,7 @@ function createExistingImportMap(importingFile: SourceFile, program: Program) {
     }
 
     return {
-        getImportsForExportInfo: ({ moduleSymbol, exportKind, targetFlags, symbol }: SymbolExportInfo): readonly FixAddToExistingImportInfo[] => {
+        getImportsForExportInfo: ({ moduleSymbol, exportKind, targetFlags, symbol }: SymbolExportInfo | FutureSymbolExportInfo): readonly FixAddToExistingImportInfo[] => {
             const matchingDeclarations = importMap?.get(getSymbolId(moduleSymbol));
             if (!matchingDeclarations) return emptyArray;
 

src/services/pasteEdits.ts

@@ -0,0 +1,115 @@
+import { addRange } from "../compiler/core";
+import {
+    CancellationToken,
+    Program,
+    SourceFile,
+    Statement,
+    SymbolFlags,
+    TextRange,
+    UserPreferences,
+} from "../compiler/types";
+import { getLineOfLocalPosition } from "../compiler/utilities";
+import {
+    codefix,
+    Debug,
+    fileShouldUseJavaScriptRequire,
+    forEachChild,
+    formatting,
+    getQuotePreference,
+    isIdentifier,
+    textChanges,
+} from "./_namespaces/ts";
+import { addTargetFileImports } from "./refactors/helpers";
+import {
+    addExportsInOldFile,
+    getExistingLocals,
+    getUsageInfo,
+} from "./refactors/moveToFile";
+import {
+    CodeFixContextBase,
+    FileTextChanges,
+    LanguageServiceHost,
+    PasteEdits,
+} from "./types";
+
+const fixId = "providePostPasteEdits";
+/** @internal */
+export function pasteEditsProvider(
+    targetFile: SourceFile,
+    pastedText: string[],
+    pasteLocations: TextRange[],
+    copiedFrom: { file: SourceFile; range: TextRange[]; } | undefined,
+    host: LanguageServiceHost,
+    preferences: UserPreferences,
+    formatContext: formatting.FormatContext,
+    cancellationToken: CancellationToken,
+): PasteEdits {
+    const changes: FileTextChanges[] = textChanges.ChangeTracker.with({ host, formatContext, preferences }, changeTracker => pasteEdits(targetFile, pastedText, pasteLocations, copiedFrom, host, preferences, formatContext, cancellationToken, changeTracker));
+    return { edits: changes, fixId };
+}
+
+function pasteEdits(
+    targetFile: SourceFile,
+    pastedText: string[],
+    pasteLocations: TextRange[],
+    copiedFrom: { file: SourceFile; range: TextRange[]; } | undefined,
+    host: LanguageServiceHost,
+    preferences: UserPreferences,
+    formatContext: formatting.FormatContext,
+    cancellationToken: CancellationToken,
+    changes: textChanges.ChangeTracker,
+) {
+    let actualPastedText: string[] | undefined;
+    if (pastedText.length !== pasteLocations.length) {
+        actualPastedText = pastedText.length === 1 ? pastedText : [pastedText.join("\n")];
+    }
+    pasteLocations.forEach((paste, i) => {
+        changes.replaceRangeWithText(
+            targetFile,
+            { pos: paste.pos, end: paste.end },
+            actualPastedText ?
+                actualPastedText[0] : pastedText[i],
+        );
+    });
+
+    const statements: Statement[] = [];
+
+    let newText = targetFile.text;
+    for (let i = pasteLocations.length - 1; i >= 0; i--) {
+        const { pos, end } = pasteLocations[i];
+        newText = actualPastedText ? newText.slice(0, pos) + actualPastedText[0] + newText.slice(end) : newText.slice(0, pos) + pastedText[i] + newText.slice(end);
+    }
+
+    Debug.checkDefined(host.runWithTemporaryFileUpdate).call(host, targetFile.fileName, newText, (updatedProgram: Program, originalProgram: Program | undefined, updatedFile: SourceFile) => {
+        const importAdder = codefix.createImportAdder(updatedFile, updatedProgram, preferences, host);
+        if (copiedFrom?.range) {
+            Debug.assert(copiedFrom.range.length === pastedText.length);
+            copiedFrom.range.forEach(copy => {
+                addRange(statements, copiedFrom.file.statements, getLineOfLocalPosition(copiedFrom.file, copy.pos), getLineOfLocalPosition(copiedFrom.file, copy.end) + 1);
+            });
+            const usage = getUsageInfo(copiedFrom.file, statements, originalProgram!.getTypeChecker(), getExistingLocals(updatedFile, statements, originalProgram!.getTypeChecker()));
+            Debug.assertIsDefined(originalProgram);
+            const useEsModuleSyntax = !fileShouldUseJavaScriptRequire(targetFile.fileName, originalProgram, host, !!copiedFrom.file.commonJsModuleIndicator);
+            addExportsInOldFile(copiedFrom.file, usage.targetFileImportsFromOldFile, changes, useEsModuleSyntax);
+            addTargetFileImports(copiedFrom.file, usage.oldImportsNeededByTargetFile, usage.targetFileImportsFromOldFile, originalProgram.getTypeChecker(), updatedProgram, importAdder);
+        }
+        else {
+            const context: CodeFixContextBase = {
+                sourceFile: updatedFile,
+                program: originalProgram!,
+                cancellationToken,
+                host,
+                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);
+            });
+        }
+        importAdder.writeFixes(changes, getQuotePreference(copiedFrom ? copiedFrom.file : targetFile, preferences));
+    });
+}

src/services/refactors/moveToFile.ts

@@ -307,7 +307,8 @@ export function deleteUnusedOldImports(oldFile: SourceFile, toMove: readonly Sta
     }
 }
 
-function addExportsInOldFile(oldFile: SourceFile, targetFileImportsFromOldFile: Map<Symbol, boolean>, changes: textChanges.ChangeTracker, useEsModuleSyntax: boolean) {
+/** @internal */
+export function addExportsInOldFile(oldFile: SourceFile, targetFileImportsFromOldFile: Map<Symbol, boolean>, changes: textChanges.ChangeTracker, useEsModuleSyntax: boolean) {
     const markSeenTop = nodeSeenTracker(); // Needed because multiple declarations may appear in `const x = 0, y = 1;`.
     targetFileImportsFromOldFile.forEach((_, symbol) => {
         if (!symbol.declarations) {
@@ -1118,7 +1119,8 @@ function getOverloadRangeToMove(sourceFile: SourceFile, statement: Statement) {
     return undefined;
 }
 
-function getExistingLocals(sourceFile: SourceFile, statements: readonly Statement[], checker: TypeChecker) {
+/** @internal */
+export function getExistingLocals(sourceFile: SourceFile, statements: readonly Statement[], checker: TypeChecker) {
     const existingLocals = new Set<Symbol>();
     for (const moduleSpecifier of sourceFile.imports) {
         const declaration = importFromModuleSpecifier(moduleSpecifier);