Function findPrecedingMatchingToken

test/fixtures/snapshot/typescript.js:127739–127774

(token, matchingTokenKind, sourceFile)

    }
    ts.isInsideJsxElement = isInsideJsxElement;
    function findPrecedingMatchingToken(token, matchingTokenKind, sourceFile) {
        var closeTokenText = ts.tokenToString(token.kind);
        var matchingTokenText = ts.tokenToString(matchingTokenKind);
        var tokenFullStart = token.getFullStart();
        // Text-scan based fast path - can be bamboozled by comments and other trivia, but often provides
        // a good, fast approximation without too much extra work in the cases where it fails.
        var bestGuessIndex = sourceFile.text.lastIndexOf(matchingTokenText, tokenFullStart);
        if (bestGuessIndex === -1) {
            return undefined; // if the token text doesn't appear in the file, there can't be a match - super fast bail
        }
        // we can only use the textual result directly if we didn't have to count any close tokens within the range
        if (sourceFile.text.lastIndexOf(closeTokenText, tokenFullStart - 1) < bestGuessIndex) {
            var nodeAtGuess = findPrecedingToken(bestGuessIndex + 1, sourceFile);
            if (nodeAtGuess && nodeAtGuess.kind === matchingTokenKind) {
                return nodeAtGuess;
            }
        }
        var tokenKind = token.kind;
        var remainingMatchingTokens = 0;
        while (true) {
            var preceding = findPrecedingToken(token.getFullStart(), sourceFile);
            if (!preceding) {
                return undefined;
            }
            token = preceding;
            if (token.kind === matchingTokenKind) {
                if (remainingMatchingTokens === 0) {
                    return token;
                }
                remainingMatchingTokens--;
            }
            else if (token.kind === tokenKind) {
                remainingMatchingTokens++;
            }
        }
    }
    ts.findPrecedingMatchingToken = findPrecedingMatchingToken;
    function removeOptionality(type, isOptionalExpression, isOptionalChain) {
        return isOptionalExpression ? type.getNonNullableType() :