tests: select testdb and use MySQL 8.0 by default

[dveeden]

• Without the USE... in TestExecuteMultiple the test panics as the result in conn_test.go:108 is nil. This doesn't seem to happen consistently. Seems to happen with both 5.7 and 8.0.
• Use MySQL 8.0 instead of MySQL 5.7
• Add Go 1.20
• Upgrade actions/setup-go
• Include OS name in the name of the test

$ go test

----------------------------------------------------------------------
PANIC: conn_test.go:92: connTestSuite.TestExecuteMultiple

... Panic: runtime error: invalid memory address or nil pointer dereference (PC=0x438592)

/usr/lib/golang/src/runtime/panic.go:884
  in gopanic
/usr/lib/golang/src/runtime/panic.go:260
  in panicmem
/usr/lib/golang/src/runtime/signal_unix.go:837
  in sigpanic
conn_test.go:108
  in connTestSuite.TestExecuteMultiple.func1
conn.go:273
  in Conn.ExecuteMultiple
conn_test.go:101
  in connTestSuite.TestExecuteMultiple
/usr/lib/golang/src/reflect/value.go:370
  in Value.Call
/home/dvaneeden/go/pkg/mod/github.com/pingcap/[email protected]/check.go:836
  in suiteRunner.forkTest.func1
/home/dvaneeden/go/pkg/mod/github.com/pingcap/[email protected]/check.go:730
  in suiteRunner.forkCall.func1
/usr/lib/golang/src/runtime/asm_amd64.s:1598
  in goexit

----------------------------------------------------------------------
FAIL: conn_test.go:132: connTestSuite.TestExecuteSelectStreaming

conn_test.go:170:
    c.Assert(err, IsNil)
... value *mysql.MyError = &mysql.MyError{Code:0x416, Message:"No database selected", State:"3D000"} ("ERROR 1046 (3D000): No database selected")

----------------------------------------------------------------------
FAIL: conn_test.go:86: connTestSuite.TestFieldList

conn_test.go:88:
    c.Assert(err, IsNil)
... value *mysql.MyError = &mysql.MyError{Code:0x416, Message:"No database selected", State:"3D000"} ("ERROR 1046 (3D000): No database selected")

----------------------------------------------------------------------
FAIL: conn_test.go:38: connTestSuite.TearDownSuite

conn_test.go:43:
    s.testExecute_DropTable(c)
conn_test.go:83:
    c.Assert(err, IsNil)
... value *mysql.MyError = &mysql.MyError{Code:0x416, Message:"No database selected", State:"3D000"} ("ERROR 1046 (3D000): No database selected")

OOPS: 18 passed, 3 FAILED, 1 PANICKED
--- FAIL: Test (0.46s)
FAIL
exit status 1
FAIL	github.com/go-mysql-org/go-mysql/client	0.465s

[atercattus]

We have "Protect matching branches" for the main branch which is based on full name like "Tests Go 1.18".
If we will use a 5 matrix.go with a 2 matrix.os we need to have 10 protection rules.

I suggest supporting only the last 2 or 3 versions of Go.

@lance6716 what do you think about this?

[dveeden]

When I created this PR there were 4 Go versions. Now (since 1bd36e6) there are only 3 Go versions. So instead of 4x2=8 there are 3x2=6 matrix combinations.

https://endoflife.date/go shows that only 1.20 and 1.19 are supported upstream (the release policy is on https://go.dev/doc/devel/release)

[lance6716]

@dveeden Hi, would you mind I resolve git conflicts directly in your PR?

[dveeden]

@dveeden Hi, would you mind I resolve git conflicts directly in your PR?

Done

[lance6716]

Thanks! we now keep golang, OS of testing image and MySQL all up-to-date