The error "Object is possibly null or undefined" is ambiguous.

[tinganho]

I have problem distinguishing if the accessor options or headers or both is possibly undefined or null below.

Can it instead of using the text Object is possibly... output the accessor expression 'this.option.headers' is possibly ...?

[mhegazy]

we can not write the full expression, this could be a function call, a function expression, a whole program .. the error span seems correct to me.

@sandersn and @DanielRosenwasser any ideas on making this error message better?

[DanielRosenwasser]

You could have a more helpful error message when the possibly null value is an identifier or property/element access, For more complex expressions, just default to the other one.

An alternative is to check for each of the possible forms and report the specifics.

• Cannot access property '{0}' on a possibly null or undefined value.
• Cannot access element on a possibly null or undefined value.
• Cannot call a possibly null or undefined value.
• Cannot construct a possibly null or undefined value.
• Any other forms I might not be thinking of.

[sandersn]

If you change the code so that it's options that could be undefined or null, then doesn't the error span shrink to this.options? That seems like it distinguishes well enough between this.options and this.options.headers as the source of the message.

[tinganho]

Though it is not every time I just look at my IDE. I some time look at the output of my terminal.

[DanielRosenwasser]

@tinganho the --pretty compiler option should give some context on what the error span refers to.

I generally agree with @sandersn though, I'd like to see if this is a problem a lot of people run into.

[gertcuykens]

Not sure if this is related but I have no idea why I get the same error when I try

    const l = document.querySelector('link[rel="import"]') as HTMLLinkElement                                                                    
    if (l == null || l == undefined) return;
    const t = l.import.querySelector('template')

[gertcuykens]

Doh! Sorry I needed to do if (l.import == null ) return;

[fcrespo82]

Is this issue still open? Can I go for it? Any pointers what file should I go for this fix?