error TS1345: An expression of type 'void' cannot be tested for truthiness - console.log(x) || x

[rolandpeelen]

In a functional context, I often use loggers like this;

const logger = (...args) => console.log(args) || args;

As console.log() returns undefined, it will always fall through the next argument. However, my angular project now no longer compiles.

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TypeScript Version: 3.1.4

Search Terms:
error TS1345: An expression of type 'void' cannot be tested for truthiness
found some issues, but not the same.
Code

const logger = (...args) => console.log(args) || args;

Expected behavior:
Compile

Actual behavior:
gives error

[j-oliveras]

Change it to use comma operator:

const logger = (...args) => (console.log(args), args);

See the discussion about this change: #26262.

[j-oliveras]

@RyanCavanaugh or @DanielRosenwasser, probably you should add Use of 'void' in control flow constructs is now disallowed to the breaking changes wiki page.

[rolandpeelen]

closed as duplicate