Crash in getJSDocTags with typescript 2.9.2

[marvec]

I saw similar issues around alredy but not this specific place. It happens when buildOptimizer and sourceMap are both true:

Module build failed: Error: Debug Failure. False expression.
    at getJSDocTags (/home/.../node_modules/typescript/lib/typescript.js:13197:22)
    at getFirstJSDocTag (/home/.../node_modules/typescript/lib/typescript.js:13205:24)
    at Object.getJSDocType (/home/.../node_modules/typescript/lib/typescript.js:13173:19)
    at getContextualSignature (/home/.../node_modules/typescript/lib/typescript.js:41002:32)
    at checkFunctionExpressionOrObjectLiteralMethod (/home/.../node_modules/typescript/lib/typescript.js:44621:43)
    at checkExpressionWorker (/home/.../node_modules/typescript/lib/typescript.js:45681:28)
    at checkExpression (/home/.../node_modules/typescript/lib/typescript.js:45609:42)
    at checkBinaryLikeExpression (/home/.../node_modules/typescript/lib/typescript.js:45155:29)
    at checkBinaryExpression (/home/.../node_modules/typescript/lib/typescript.js:45147:20)
    at checkExpressionWorker (/home/.../node_modules/typescript/lib/typescript.js:45702:28)
    at checkExpression (/home/.../node_modules/typescript/lib/typescript.js:45609:42)
    at checkExpressionCached (/home/.../node_modules/typescript/lib/typescript.js:45457:38)
    at getTypeOfExpression (/home/.../node_modules/typescript/lib/typescript.js:45577:28)
    at checkDeclarationInitializer (/home/.../node_modules/typescript/lib/typescript.js:45469:24)
    at getTypeForVariableLikeDeclaration (/home/.../node_modules/typescript/lib/typescript.js:30738:28)
    at getWidenedTypeForVariableLikeDeclaration (/home/.../node_modules/typescript/lib/typescript.js:30961:24)

I have no idea which comment in the polygon.js causes that. I am able to provide the source code. The package is plotly.js 1.39.4.

npm 6.3.0

[ghost]

May be a duplicate of #25067 -- please test with typescript@next.

[marvec]

This seems to be the problematic code that make typescript fail:

/**
 * Test if a segment of a points array is bent or straight
 *
 * @param pts Array of [x, y] pairs
 * @param start the index of the proposed start of the straight section
 * @param end the index of the proposed end point
 * @param tolerance the max distance off the line connecting start and end
 *      before the line counts as bent
 * @returns boolean: true means this segment is bent, false means straight
 */
var isBent = polygon.isSegmentBent = function isBent(pts, start, end, tolerance) {
    var startPt = pts[start],
        segment = [pts[end][0] - startPt[0], pts[end][1] - startPt[1]],
        segmentSquared = dot(segment, segment),
        segmentLen = Math.sqrt(segmentSquared),
        unitPerp = [-segment[1] / segmentLen, segment[0] / segmentLen],
        i,
        part,
        partParallel;

    for(i = start + 1; i < end; i++) {
        part = [pts[i][0] - startPt[0], pts[i][1] - startPt[1]];
        partParallel = dot(part, segment);

        if(partParallel < 0 || partParallel > segmentSquared ||
            Math.abs(dot(part, unitPerp)) > tolerance) return true;
    }
    return false;
};

[marvec]

And my wild guess is that this can be the cause - #24997 and #24996

[marvec]

@Andy-MS Unfortunatelly, I am not able to try with typescript@next easily. Our project has a lot of dependencies that are incompatible with typescript>2.10. I spent half an hour trying to make it it work but without luck. Is there just a change/patch I can introduce in typescript to verify it?

[ghost]

We're not likely to backport that change to ts2.9 at this point. What dependencies are incomatible with ts3.0?

[marvec]

@Andy-MS It is probably the same case as #25067 because when I split the defnition in the problematic file like the following, it went fine:

polygon.isSegmentBent = function isBent( ....
...
var isBent = polygon.isSegmentBent;

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.