test: expand reaper database.go coverage

[Abdelrhmansersawy]

fixes: #1099

Expand test coverage for reaper/database.go through handling:

• query validation and error propagation
• protocol selection for non‑Postgres sources
• argument preservation for query execution
• instance health checks via ping (up/down/PgBouncer)
• extension creation decision paths (available/missing/query failure)

Test coverage improvements:

sersawy@omarchy ~/W/g/pgwatch (testcoverage_reaper)> rg "^total:" /tmp/cover.reaper.before.txt
                                                     rg "^total:" /tmp/cover.reaper.after.txt
61:total:                                                                                       (statements)                            56.5%
61:total:                                                                                       (statements)                            59.0%

[coveralls]

Pull Request Test Coverage Report for Build 21356387862

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.8%) to 76.116%

---

Totals
Change from base Build 21290566757:	0.8%
Covered Lines:	4057
Relevant Lines:	5330

---

💛 - Coveralls

[Abdelrhmansersawy]

@0xgouda
Could you please take a look and let me know if I’m heading in the right direction? I’m planning to complete this PR before moving on to other reaper files to improve coverage, unless you’d recommend working on them in parallel.

[0xgouda]

@Abdelrhmansersawy

I don't understand whether this PR is ready for review or not. If not, please convert it to draft.

Anyway, I take a fast look and the TestQueryMeasurements... is repeated many times, shouldn't all tests for QueryMeasurements() go into a single function that tests different cases/scenarios?

Also please keep in mind this isn't about increasing test coverage but rather low test coverage hints that we have important paths not covered by tests, so you may consider adding integration tests under cmd/pgwatch/ and/or writing many scenarios to test the function not just covering the lines.

so for example, if database.go ended up with 80% coverage but we have tested all improtant/critical stuff we are golden.

[Abdelrhmansersawy]

So, you want me to work on adding tests under cmd/pgwatch/ that test the whole system working together, not isolated units (e.g. database_test.go) ?

[0xgouda]

So, you want me to work on adding tests under cmd/pgwatch/ that test the whole system working together, not isolated units (e.g. database_test.go) ?

Let's have a quick call, ping me on slack if you are active now.

[Abdelrhmansersawy]

So, you want me to work on adding tests under cmd/pgwatch/ that test the whole system working together, not isolated units (e.g. database_test.go) ?

Let's have a quick call, ping me on slack if you are active now.

I have been ping you on slack now.

[pashagolub]

hey, would you please resolve if it's still up to date