Fix the out of boundary error

[zli82016]

fixes hashicorp/terraform-provider-google#16439

Release Note Template for Downstream PRs (will be copied)

monitoring: fixed the index out of range crash when removing metrics from `dashboard_json` for the resource `google_monitoring_dashboard`

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

Terraform GA: Diff ( 2 files changed, 56 insertions(+), 1 deletion(-))
Terraform Beta: Diff ( 2 files changed, 56 insertions(+), 1 deletion(-))

[modular-magician]

Tests analytics

Total tests: 3292
Passed tests 2953
Skipped tests: 338
Affected tests: 1

Action taken

Found 1 affected test(s) by replaying old test recordings. Starting RECORDING based on the most recent commit. Click here to see the affected tests

TestAccMonitoringDashboard_update

Get to know how VCR tests work

[modular-magician]

$\textcolor{green}{\textsf{Tests passed during RECORDING mode:}}$
TestAccMonitoringDashboard_update[Debug log]

Rerun these tests in REPLAYING mode to catch issues

$\textcolor{green}{\textsf{No issues found for passed tests after REPLAYING rerun.}}$

---

$\textcolor{green}{\textsf{All tests passed!}}$
View the build log or the debug log for each test

[c2thorn]

small suggestion for release note:
error -> crash ?
Also thanks for adding the test scenario!

[etruong42]

The release note says fixed the index out of range crash in dashboard_json perma-diffs - what does "perma-diff" mean in this context? Perma-diff was a symptom of a bug. Is there a "perma-diff" function here that had an index out of range?

[etruong42]

Does the addition of this test mean that updating the grid layout is sufficient to trigger the index out of range crash?

If so, thank you for adding this to prevent a future regression!

[etruong42]

Actually, it appears there is already testAccMonitoringDashboard_gridLayout - maybe this deserves a comment as to how this is different? Fwiw, I can't tell from the name how the intention behind testAccMonitoringDashboard_gridLayoutUpdate is supposed to be different from testAccMonitoringDashboard_gridLayout

[zli82016]

This test triggers the index out of range crash. With the fix in this PR, this test passed.

[zli82016]

Yeah, the comment will help.

[etruong42]

What do each of these fields e.g. ImportState do? I read what appears to be the relevant document at https://googlecloudplatform.github.io/magic-modules/develop/test/ - perhaps I am missing something?

[zli82016]

These fields are used to test if importing the resource works or not.

ImportState triggers the import testing mode. ImportStateVerify will compare the state after import with the server side response. ImportStateVerifyIgnore will not compare the ignored fields.

[zli82016]

The release note says fixed the index out of range crash in dashboard_json perma-diffs - what does "perma-diff" mean in this context? Perma-diff was a symptom of a bug. Is there a "perma-diff" function here that had an index out of range?

"perma-diff" function here means the DiffSuppressFunc

I modified the release note to make it more clear.