Map() does not panic on zero-initialized value

[mackjmr]

Describe the bug
The following code will not cause a panic:

var test pcommon.Value

func main() {
	test.Map()
}

although the doc states:

Calling this function on zero-initialized Value will cause a panic.

Steps to reproduce

package main

import (
	"go.opentelemetry.io/collector/pdata/pcommon"
)

var test pcommon.Value

func main() {
	test.Map()
}

What did you expect to see?
A Panic.

What did you see instead?
No Panic.

What version did you use?

require go.opentelemetry.io/collector/pdata v1.0.0

[dmitryax]

It returns a zero-initialized map which will panic after being used. Unless the comment says it panics right away, it's close to be true :)

We may complicate the logic and make sure it panics right away, but I'm not sure it's worth it. Maybe just updating the comment is good enough. Something like

// Map returns the map value associated with this Value.
// If the function is called on zero-initialized Value or if the Type() is not ValueTypeMap 
// then it returns an invalid map. Note that using such map can cause panic.

[mackjmr]

Maybe just updating the comment is good enough.

Agreed that updating the comment should be good enough 👍

[dmitryax]

@mackjmr I updated all the comments in value.go #9038, but it might be the same issue for other structs. It'd be great if you can submit another issue or help with resolving them as well