Misc error checking #70
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src/locator/index.ts
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| let dimension: number; | ||
| let moduleSize: number; | ||
| try { | ||
| const computedDimension = computeDimension(topLeft, topRight, bottomLeft, matrix); |
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nit: You could use destructuring here.
({ dimension, moduleSize } = computeDimension(topLeft, topRight, bottomLeft, matrix));
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Ah I was trying to do that but didn't have the syntax right. Added in a8ceef6.
src/locator/index.ts
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| @@ -62,6 +62,10 @@ function computeDimension(topLeft: Point, topRight: Point, bottomLeft: Point, ma | |||
| sum(countBlackWhiteRun(topRight, topLeft, matrix, 5)) / 7 | |||
| ) / 4; | |||
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| if (moduleSize === 0) { | |||
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Unless 0 is a magic number being returned by something, it'd probably be better to switch this to something like if (moduleSize < 1) { or whatever the smallest reasonable module size is to avoid float rounding issues.
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So at least with the test case this was triggering because countBlackWhiteRun was returning [0,0,-1,0,0] which basically means the finder patterns were too small to extract distances from. We could try throwing deeper in the stack but it felt reasonable to just check for an explicit 0 here. Thoughts?
Fixes #68 and #53.
We were seeing 2 intermittent errors.
Uncaught RangeError: Invalid typed array length: Infinityin extract. This was caused by the moduleSize calculation in locate returning 0, so returning a QR of infinite size (edgeLength/moduleSize). We now explicitly check for this case and bail out of locator. This fixes part of Error in chrome 64.0.3282.186 Win 10 #53.No changes to the end to end tests which is good, and have added explicit test cases for these failure cases.