Structured Append

[kousu]

Fixes #128 .

[kousu]

Here's some open questions:

• what should the API look for this? The current version adds an optional .structuredAppend to result objects with .M and .N subobjects. "Structured Append" is the technical name from the spec, and it matches what qrencode and zxing-cpp call this feature, but it's very abstract; I would rather it be something like .numbering.page, .numbering.of.
• the M and N are 1-based (see the QR spec (ISO 18004) section 9.2), which is annoying to work with in Javascript (and most languages). I've conformed to the spec, up-shifting the numbers so that 0<M<=N<=16, but maybe that's a mistake? Or maybe I should upshift N but not M so that you have 0<=M<N<=16, python-style?
• I couldn't figure out how to use jest to test dependent facts because it wants to take everything as callbacks that it runs in parallel. To get around this I added loadPngSync() and used assert in a couple of places instead of expect(). I'm not proud of this but I couldn't see another way. Help?

[kousu]

Another issue:

if I try to use import { strict as assert } from 'assert'; and then regenerate the test-cases, I get "Module '"assert"' has no exported member 'strict'. ":

$ ./node_modules/.bin/ts-node --project tests/ tests/generate-test-data.ts

./jsQR/node_modules/ts-node/src/index.ts:307
        throw new TSError(formatDiagnostics(diagnosticList, cwd, ts, lineOffset))
              ^
TSError: ⨯ Unable to compile TypeScript
src/decoder/decodeData/index.ts (5,10): Module '"assert"' has no exported member 'strict'. (2305)
    at getOutput (./jsQR/node_modules/ts-node/src/index.ts:307:15)
    at ./jsQR/node_modules/ts-node/src/index.ts:336:16
    at Object.compile (./jsQR/node_modules/ts-node/src/index.ts:498:11)
    at Module.m._compile (./jsQR/node_modules/ts-node/src/index.ts:392:43)
    at Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Object.require.extensions.(anonymous function) [as .ts] (./jsQR/node_modules/ts-node/src/index.ts:395:12)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Module.require (internal/modules/cjs/loader.js:637:17)

But this doesn't happen if I just ./node_modules/.bin/jest --runInBand structured-append which has the same offending line in it. How is that possible? Is generate-test-data.ts running in a stricter TypeScript mode?