Function updateLanguageServiceSourceFile

test/fixtures/snapshot/typescript.js:164806–164856

(sourceFile, scriptSnapshot, version, textChangeRange, aggressiveChecks)

    }
    ts.createLanguageServiceSourceFile = createLanguageServiceSourceFile;
    function updateLanguageServiceSourceFile(sourceFile, scriptSnapshot, version, textChangeRange, aggressiveChecks) {
        // If we were given a text change range, and our version or open-ness changed, then
        // incrementally parse this file.
        if (textChangeRange) {
            if (version !== sourceFile.version) {
                var newText = void 0;
                // grab the fragment from the beginning of the original text to the beginning of the span
                var prefix = textChangeRange.span.start !== 0
                    ? sourceFile.text.substr(0, textChangeRange.span.start)
                    : "";
                // grab the fragment from the end of the span till the end of the original text
                var suffix = ts.textSpanEnd(textChangeRange.span) !== sourceFile.text.length
                    ? sourceFile.text.substr(ts.textSpanEnd(textChangeRange.span))
                    : "";
                if (textChangeRange.newLength === 0) {
                    // edit was a deletion - just combine prefix and suffix
                    newText = prefix && suffix ? prefix + suffix : prefix || suffix;
                }
                else {
                    // it was actual edit, fetch the fragment of new text that correspond to new span
                    var changedText = scriptSnapshot.getText(textChangeRange.span.start, textChangeRange.span.start + textChangeRange.newLength);
                    // combine prefix, changed text and suffix
                    newText = prefix && suffix
                        ? prefix + changedText + suffix
                        : prefix
                            ? (prefix + changedText)
                            : (changedText + suffix);
                }
                var newSourceFile = ts.updateSourceFile(sourceFile, newText, textChangeRange, aggressiveChecks);
                setSourceFileFields(newSourceFile, scriptSnapshot, version);
                // after incremental parsing nameTable might not be up-to-date
                // drop it so it can be lazily recreated later
                newSourceFile.nameTable = undefined;
                // dispose all resources held by old script snapshot
                if (sourceFile !== newSourceFile && sourceFile.scriptSnapshot) {
                    if (sourceFile.scriptSnapshot.dispose) {
                        sourceFile.scriptSnapshot.dispose();
                    }
                    sourceFile.scriptSnapshot = undefined;
                }
                return newSourceFile;
            }
        }
        var options = {
            languageVersion: sourceFile.languageVersion,
            impliedNodeFormat: sourceFile.impliedNodeFormat,
            setExternalModuleIndicator: sourceFile.setExternalModuleIndicator,
        };
        // Otherwise, just create a new source file.
        return createLanguageServiceSourceFile(sourceFile.fileName, scriptSnapshot, options, version, /*setNodeParents*/ true, sourceFile.scriptKind);
    }
    ts.updateLanguageServiceSourceFile = updateLanguageServiceSourceFile;
    var NoopCancellationToken = {
        isCancellationRequested: ts.returnFalse,