Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Cannot read property 'toJSON' of undefined

See original GitHub issue

I have a project here that uses ngc. However, when I compile the project using TS 2.2.2 and the command ./node_modules/.bin/ngc -p src/lib/tsconfig.json I get the following error…

TypeError: Cannot read property 'toJSON' of undefined
    at Object.sourceMapGeneratorToConsumer (.../node_modules/tsickle/build/src/source_map_utils.js:65:42)
    at TsickleCompilerHost.combineSourceMaps (.../flex-layout/node_modules/tsickle/build/src/tsickle_compiler_host.js:167:74)
    at TsickleCompilerHost.writeFile (.../flex-layout/node_modules/tsickle/build/src/tsickle_compiler_host.js:111:28)
    at Object.writeFile (.../flex-layout/node_modules/typescript/lib/typescript.js:64240:132)
    at Object.writeFile (.../flex-layout/node_modules/typescript/lib/typescript.js:9020:14)
    at printSourceFileOrBundle (.../flex-layout/node_modules/typescript/lib/typescript.js:61197:20)
    at emitSourceFileOrBundle (.../flex-layout/node_modules/typescript/lib/typescript.js:61155:21)
    at Object.forEachEmittedFile (.../flex-layout/node_modules/typescript/lib/typescript.js:8986:17)
    at Object.emitFiles (.../flex-layout/node_modules/typescript/lib/typescript.js:61137:12)
    at emitWorker (.../flex-layout/node_modules/typescript/lib/typescript.js:64294:33)

I would expect that this is probably related to using TS 2.2

https://github.com/angular/tsickle/pull/447