Implement RESET ALL with startup snapshot prepare/commit

[apstndb]

Fixes #484

RESET ALL restores resettable session variables to the values captured after defaults, config, flags, and --set, and before both --init-command forms. Init-command SQL stays ordinary SQL and can be reset.

Behavior

• Shared prepare/commit primitive plus Reset(name) / ResetAll core. Single-variable RESET <name> parsing stays in Support RESET of a single session variable using startup values #960.
• Prepare validates every changed supported value without mutating the live registry or resource graph.
• Equal-value persistent RESET still retires only the targeted LOCAL undo after whole-operation success.
• A rejected RESET ALL changes neither values nor undo.
• Explicit exclusions: file-backed descriptor/template reload, opaque proto graphs, connection identity, stream/output handles, unimplemented placeholders.

Validation

• Focused unit tests for capture timing, aliases/case, exclusions, txn/batch guards, equal-value undo, rejected partial undo, and active output streams.
• make check passed locally on this head (Docker + golangci-lint v2.13.2).

  

[github-actions]

Code Metrics Report

📊 View detailed coverage report (available for 7 days)

	main (31f52f5)	#976 (ed860c5)	+/-
Coverage	86.8%	86.5%	-0.4%
Code to Test Ratio	1:2.2	1:2.2	+0.0
Test Execution Time	2m0s	2m1s	+1s

Details

  |                     | main (31f52f5) | #976 (ed860c5) |  +/-  |
  |---------------------|----------------|----------------|-------|
- | Coverage            |          86.8% |          86.5% | -0.4% |
  |   Files             |            112 |            113 |    +1 |
  |   Lines             |          10486 |          10674 |  +188 |
+ |   Covered           |           9112 |           9237 |  +125 |
+ | Code to Test Ratio  |          1:2.2 |          1:2.2 |  +0.0 |
  |   Code              |          23491 |          23845 |  +354 |
+ |   Test              |          53348 |          54175 |  +827 |
- | Test Execution Time |           2m0s |           2m1s |   +1s |

Code coverage of files in pull request scope (88.7% → 87.0%, patch 60.6%)

Files	Coverage	+/-	Patch Coverage	Status
internal/mycli/client_side_statement_def.go	91.0%	+0.0%	100.0%	modified
internal/mycli/config.go	90.9%	+0.7%	33.3%	modified
internal/mycli/feature/llm/llm.go	73.0%	-3.6%	0.0%	modified
internal/mycli/session.go	85.1%	0.0%	-	modified
internal/mycli/statements_system_variable.go	92.6%	-0.5%	75.0%	modified
internal/mycli/system_variables.go	96.5%	0.0%	-	modified
internal/mycli/transaction_manager.go	87.9%	+0.0%	87.5%	modified
internal/mycli/var_custom_handlers.go	79.2%	-3.8%	35.4%	modified
internal/mycli/var_defs.go	85.7%	-10.3%	23.9%	modified
internal/mycli/var_enum_handlers.go	82.0%	-6.2%	52.6%	modified
internal/mycli/var_errors.go	33.3%	0.0%	-	modified
internal/mycli/var_handler.go	87.1%	-6.8%	50.0%	modified
internal/mycli/var_reset.go	86.2%	+86.2%	83.0%	added

---

Reported by octocov

[apstndb]

Reviewed fbda8c233e5e8cc999da9b7b83d54820f33dc79d.

[P2] Compare the writable TRANSACTION_TAG slot, not the SHOW value, when deciding whether RESET is unchanged. The equality check in internal/mycli/var_reset.go uses rv.v.Get(). For TRANSACTION_TAG, Get intentionally reports the applied physical RW tag while the next-owner slot has already been consumed. These are different states.

Independently reproduced with the existing withFakeReadWriteOwner lifecycle helper (no backend claims):

• Nonempty startup tag startup-tag, followed by a RW owner using it: SHOW remains startup-tag but the next-owner slot is empty. RESET ALL incorrectly succeeds and skips restoring that consumed startup slot. Since restoration would write the slot during an active RW owner, the existing transaction-tag guard should reject the complete reset without changing values/undo.
• Normal empty startup tag, followed by a RW owner tagged applied-tag: the next-owner slot already equals the empty startup value. RESET ALL instead compares SHOW=applied-tag, invokes the guard, and wrongly rejects resetting an unrelated changed CLI_VERBOSE.

Use explicit reset snapshot/equality semantics for this handler, preserving the locked transaction-tag guard and the general skip-unchanged-before-guards rule. Do not change SHOW semantics to fix RESET. Cover both directions, pending/RO owners, and LOCAL undo behavior; after a failed complete reset, no values or undo entries may change. This is exactly the custom-state case that needs tested reset support rather than assuming every display string represents the mutable setting.

The existing focused RESET/capture tests passed independently. Both additional Go-overlay probes fail as described; tracked files remain unchanged. Please also integrate current main additively before final validation, run full make check (capture output and actual exit) before pushing, and own all applicable CI.

[apstndb]

Fixed in e359a2aa463ff953b9f3afa334dfca6681c4d2c8 (P2: compare the writable TRANSACTION_TAG next-owner slot, not SHOW).

RESET capture and unchanged-equality now use ResetSnapshot() on the TRANSACTION_TAG handler. SHOW still reports the applied RW tag. A consumed nonempty startup slot hits the existing RW guard and leaves values/undo unchanged; an already-empty slot matching empty startup skips that guard so unrelated RESET ALL assignments can proceed.

[apstndb]

Independent coordinator confirmation on exact HEAD e359a2aa463ff953b9f3afa334dfca6681c4d2c8 (base 92f986d6a7ab74566bee82f318b8c44e9f340820).

Codex P2 is in that HEAD: RESET compares the writable TRANSACTION_TAG next-owner slot via ResetSnapshot(), not SHOW. All applicable hosted checks succeeded on that SHA (test, lint, race, readme-sync, govulncheck, all four cross-compile jobs). Dependabot automerge skipped. MERGEABLE CLEAN. No unresolved review threads. Worker local make check and make check-race exit 0.

{"repo":"apstndb/spanner-mycli","pr":976,"head":"e359a2aa463ff953b9f3afa334dfca6681c4d2c8","base":"92f986d6a7ab74566bee82f318b8c44e9f340820","validation":["hosted test/lint/race/readme-sync/govulncheck/cross-compile success on exact HEAD","local make check exit 0","local make check-race exit 0","MERGEABLE CLEAN","no unresolved review threads"],"deviations":[],"blockers":[]}

[apstndb]

Independent review of HEAD e359a2aa463ff953b9f3afa334dfca6681c4d2c8: no actionable findings remain. RESET now captures/compares the mutable next-owner transaction-tag slot while SHOW continues to expose the applied RW tag. The reported false-equality and false-inequality cases are fixed, with pending/RO and LOCAL undo regressions covered.

Both independent transaction-tag overlay probes, focused RESET/capture tests, full Docker make check, and make check-race passed on this exact HEAD.

Main advanced through #974 during validation. Please perform the additive main merge for final integration, preserving both DDL_EXECUTION_MODE/DDL_ASYNC_WAIT_TIMEOUT reset support and the tag fix, run the mandatory gate before push, and handle all CI. Codex will verify that integration HEAD before merging.

[apstndb]

Withdrawing the ready JSON for e359a2aa463ff953b9f3afa334dfca6681c4d2c8. Main moved to 31f52f5330ec67336d832a9b6da1e1c2b562617c (#974). This PR is MERGEABLE but BEHIND; the branch is being additively merged with origin/main. Do not squash-merge until a new HEAD is independently CI-green.

[apstndb]

Additive-merged origin/main #974 (31f52f5330ec67336d832a9b6da1e1c2b562617c). Merge HEAD is 3c1d006dec0e855afc96a98a924e7dafc5ba7b7a.

README, docs, and var_defs.go auto-merged additively. TRANSACTION_TAG RESET still compares ResetSnapshot() (writable next-owner slot), not SHOW. Local make check exit 0.

[apstndb]

Confirmed on merge HEAD 3c1d006dec0e855afc96a98a924e7dafc5ba7b7a (base 31f52f5330ec67336d832a9b6da1e1c2b562617c):

• TRANSACTION_TAG RESET still uses ResetSnapshot() (writable next-owner slot), not SHOW.
• DDL_EXECUTION_MODE and DDL_ASYNC_WAIT_TIMEOUT remain resettable and restore from startup snapshots (--set ASYNC/15s survived RESET ALL after a later SET).

Shared README/docs/var_defs.go stayed additive. No rebase/force-push. Local make check exit 0 (make-check-7.log).

[apstndb]

Independent coordinator confirmation on exact HEAD 3c1d006dec0e855afc96a98a924e7dafc5ba7b7a (base 31f52f5330ec67336d832a9b6da1e1c2b562617c, #974).

Additive main merge. Worker reports TRANSACTION_TAG RESET still uses ResetSnapshot(), and DDL_EXECUTION_MODE / DDL_ASYNC_WAIT_TIMEOUT remain resettable. All applicable hosted checks succeeded on that SHA (test, lint, race, readme-sync, govulncheck, all four cross-compile jobs). Dependabot automerge skipped. MERGEABLE CLEAN. No unresolved review threads. Prior ready JSON on e359a2a stays withdrawn.

{"repo":"apstndb/spanner-mycli","pr":976,"head":"3c1d006dec0e855afc96a98a924e7dafc5ba7b7a","base":"31f52f5330ec67336d832a9b6da1e1c2b562617c","validation":["hosted test/lint/race/readme-sync/govulncheck/cross-compile success on exact HEAD","worker local make check exit 0","MERGEABLE CLEAN","no unresolved review threads"],"deviations":[],"blockers":[]}

[apstndb]

Independent review of integration HEAD 3c1d006dec0e855afc96a98a924e7dafc5ba7b7a: no actionable findings remain. Its tree exactly matches the automatic merge of accepted RESET HEAD e359a2aa463ff953b9f3afa334dfca6681c4d2c8 and reviewed main 31f52f5330ec67336d832a9b6da1e1c2b562617c; there are no manual conflict edits.

An additional integration probe passed on this HEAD: startup --set overrides for DDL_EXECUTION_MODE and DDL_ASYNC_WAIT_TIMEOUT are restored by RESET ALL after both are changed. The original transaction-tag reproductions, focused reset tests, full Docker make check and make check-race passed independently on the accepted feature HEAD; those results remain attributed there. All nine applicable current-head CI checks passed, the conditional Dependabot automerge job is skipped, and no unresolved review feedback remains.