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fix \N{ (named unicode characters) in strings being turned into f-strings #1504

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Merged
merged 2 commits into from
Sep 22, 2025
Merged

fix \N{ (named unicode characters) in strings being turned into f-strings #1504

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40095e2
fix `\N{` (named unicode characters) in strings being turned into f-s…
DetachHead Sep 22, 2025
040d234
fix `onTypeFormatting` tests
DetachHead Sep 22, 2025
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14 changes: 12 additions & 2 deletions packages/pyright-internal/src/languageServerBase.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -1631,8 +1631,18 @@ export abstract class LanguageServerBase implements LanguageServerInterface, Dis
// other string types that can't be used with f-strings
!(node.d.token.flags & (StringTokenFlags.Bytes | StringTokenFlags.Unicode | StringTokenFlags.Template))
) {
const position = convertOffsetToPosition(node?.start, parseResults.tokenizerOutput.lines);
return [{ range: { start: position, end: position }, newText: 'f' }];
// don't do it if the previous characters are "\N{" because the user is likely trying to use a named unicode character, not an f-string
const dontConvertToFstringIfPrefix = '\\N{';
const positionInString = offset - node.start - node.d.token.quoteMarkLength;
if (
node.d.token.escapedValue.slice(
positionInString - dontConvertToFstringIfPrefix.length,
positionInString
) !== dontConvertToFstringIfPrefix
) {
const position = convertOffsetToPosition(node?.start, parseResults.tokenizerOutput.lines);
return [{ range: { start: position, end: position }, newText: 'f' }];
}
}
return;
};
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51 changes: 40 additions & 11 deletions packages/pyright-internal/src/tests/languageServer.test.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ import {
CompletionRequest,
ConfigurationItem,
DiagnosticSeverity,
DidChangeTextDocumentNotification,
DocumentOnTypeFormattingRequest,
InitializedNotification,
InitializeRequest,
Expand Down Expand Up @@ -172,10 +173,17 @@ describe(`Basic language server tests`, () => {
assert(completionItem);
});
describe('onTypeFormatting', () => {
const checkOnTypeFormatting = async (stringPrefix: string, shouldConvertString: boolean) => {
const caret = '[|/*marker*/|]';
const checkOnTypeFormatting = async (options: {
stringPrefix?: string;
stringContent?: string;
quoteCount: 1 | 3;
shouldConvertString: boolean;
}) => {
const quotes = options.quoteCount === 3 ? '"""' : '"';
const code = `
// @filename: test.py
//// foo = ${stringPrefix}"[|/*marker*/|]"
//// foo = ${options.stringPrefix ?? ''}${quotes}${options.stringContent ?? caret}${quotes}
`;
const info = await runLanguageServer(DEFAULT_WORKSPACE_ROOT, code, /* callInitialize */ true);

Expand All @@ -184,17 +192,25 @@ describe(`Basic language server tests`, () => {
const fileUri = marker.fileUri;
const text = info.testData.files.find((d) => d.fileName === marker.fileName)!.content;
const parseResult = getParseResults(text);
const position = convertOffsetToPosition(marker.position, parseResult.tokenizerOutput.lines);
// need to send this notification first before onTypeFormatting.
// see https://github.com/microsoft/language-server-protocol/issues/1053#issuecomment-725468469
await info.connection.sendNotification(DidChangeTextDocumentNotification.type, {
textDocument: { uri: fileUri.toString(), version: 2 },
contentChanges: [{ range: { start: position, end: position }, text: '{}' }],
});
const onTypeFormattingRequest = await info.connection.sendRequest(
DocumentOnTypeFormattingRequest.type,
{
textDocument: { uri: fileUri.toString() },
position: convertOffsetToPosition(marker.position, parseResult.tokenizerOutput.lines),
// need to add 1 to the position because it's inserting a character (i think)
position: { line: position.line, character: position.character + 1 },
ch: '{',
options: { insertSpaces: true, tabSize: 4 },
},
CancellationToken.None
);
if (shouldConvertString) {
if (options.shouldConvertString) {
const expectedPosition = { character: 6, line: 0 };
tExpect(onTypeFormattingRequest).toEqual([
{ newText: 'f', range: { start: expectedPosition, end: expectedPosition } },
Expand All @@ -203,13 +219,26 @@ describe(`Basic language server tests`, () => {
tExpect(onTypeFormattingRequest).toBeNull();
}
};
test('normal string', () => checkOnTypeFormatting('', true));
test('already f-string', () => checkOnTypeFormatting('f', false));
test('r-string', () => checkOnTypeFormatting('r', true));
test('bytes', () => checkOnTypeFormatting('b', false));
test('t-string', () => checkOnTypeFormatting('t', false));
test('u-string', () => checkOnTypeFormatting('u', false));
test('r-string and b-string', () => checkOnTypeFormatting('rb', false));
test('normal string', () => checkOnTypeFormatting({ quoteCount: 1, shouldConvertString: true }));
test('already f-string', () =>
checkOnTypeFormatting({ stringPrefix: 'f', quoteCount: 1, shouldConvertString: false }));
test('r-string', () => checkOnTypeFormatting({ stringPrefix: 'r', quoteCount: 1, shouldConvertString: true }));
test('bytes', () => checkOnTypeFormatting({ stringPrefix: 'b', quoteCount: 1, shouldConvertString: false }));
test('t-string', () => checkOnTypeFormatting({ stringPrefix: 't', quoteCount: 1, shouldConvertString: false }));
test('u-string', () => checkOnTypeFormatting({ stringPrefix: 'u', quoteCount: 1, shouldConvertString: false }));
test('r-string and b-string', () =>
checkOnTypeFormatting({ stringPrefix: 'rb', quoteCount: 1, shouldConvertString: false }));
test('multiline string', () => checkOnTypeFormatting({ quoteCount: 3, shouldConvertString: true }));
describe('named unicode characters (\\N)', () => {
test('normal', () =>
checkOnTypeFormatting({ quoteCount: 1, stringContent: `\\N${caret}`, shouldConvertString: false }));
test('multiline string', () =>
checkOnTypeFormatting({ quoteCount: 3, stringContent: `\\N${caret}`, shouldConvertString: false }));
test('other characters in the string', () =>
checkOnTypeFormatting({ quoteCount: 1, stringContent: `asdf\\N${caret}`, shouldConvertString: false }));
test('off by 1', () =>
checkOnTypeFormatting({ quoteCount: 1, stringContent: `\\N ${caret}`, shouldConvertString: true }));
});
});

[false, true].forEach((supportsPullDiagnostics) => {
Expand Down
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