Universal invariant baseline
Contract
| Field |
Bound contract |
| Trigger |
User explicitly requests an invariant-first, fail-fast, special-case-eliminating baseline for a named implementation. |
| Authority |
Reversible local: writes only the named local artifact; rollback is version control (restore) or undo (file deletion). No remote mutation. |
| Side effect |
Replace the target local file with its invariant-first, fail-fast, special-case-eliminating refinement. |
| Done |
All named invariant checks pass and no unresolved special-case artifacts remain. |
Inputs
Required:
TARGET: path to the local source file or module to baseline.LANGUAGE: the target's language (e.g., python, rust, typescript). Required to select correct invariant patterns.
Procedure
- Validate the request. Confirm
TARGET is a concrete, scoped implementation task with a named local path. If TARGET is absent, empty, or points to a non-local artifact, raise BLOCKED-INPUT and stop. Done when: TARGET is confirmed as a concrete local path.
- Enumerate invariants. For
LANGUAGE, enumerate the language-native invariant patterns that govern correctness: type contracts, ownership/borrow rules, null/void guards, resource lifecycle ordering, and domain-specific preconditions. Write each as a named, executable check with a unique identifier. Done when: every invariant pattern is a named, executable check with a unique identifier.
- Insert fail-fast guards. Before every mutable state operation, every external call, and every branching decision, insert the matching invariant check. If any check fails, halt immediately with
INVARIANT-FAIL: <identifier> and the observed violation. The target artifact is unchanged until all checks pass. Done when: every mutable state operation, external call, and branching decision has a matching invariant guard.
- Eliminate special cases. Scan the target for:
- Boolean flag arguments or module-level toggles that gate behavior.
- Hardcoded branch paths that duplicate a general case.
- Numeric or string domain constants used as inline guards.
For each found artifact, either refactor the boolean branch into a data-driven lookup, merge the special case into the general path, or convert the magic constant into a named constant with a documented invariant. Done when: no boolean flags, hardcoded duplicate branches, or inline magic constants remain.
- Re-validate. Run checks by compiling the target in its language-native build and running the existing test suite scoped to the target. If the project has no compile step, run the test suite alone. If any check fails, halt with
INVARIANT-FAIL: <identifier> listing the specific failure. Record the complete set of removed special-case artifacts as the resolution log. Done when: all invariant checks pass and the resolution log is complete.
Failure and recovery
| Failure class |
Condition |
Result |
| BLOCKED-INPUT |
TARGET absent, empty, or non-local |
Stop. No file changed. |
| INVARIANT-FAIL |
A named invariant check fails |
Stop. Artifact unchanged. Report <identifier>. |
| SPECIAL-CASE-INCOMPLETE |
Not all special-case artifacts resolved |
Stop. Report the unresolved set. |
Partial-result rule: in-place edits to the target are rolled back via VCS on failure. Run git restore TARGET to revert the working copy to its pre-edit state. If the target was a new file, delete it instead. No partial result is emitted.
Output
The target local artifact replaced with its invariant-first refinement, plus a resolution log listing every removed special case and the invariant identifier that now governs its behavior.
1---2name: universal-invariant-baseline3description: Use when invoked to apply an invariant-first, fail-fast, special-case-eliminating baseline. Not for domain models in types: use type-driven. Not for design-by-contract: use contract-driven.4---56# Universal invariant baseline78## Contract910| Field | Bound contract |11|---|---|12| Trigger | User explicitly requests an invariant-first, fail-fast, special-case-eliminating baseline for a named implementation. |13| Authority | Reversible local: writes only the named local artifact; rollback is version control (restore) or undo (file deletion). No remote mutation. |14| Side effect | Replace the target local file with its invariant-first, fail-fast, special-case-eliminating refinement. |15| Done | All named invariant checks pass and no unresolved special-case artifacts remain. |1617## Inputs1819Required:20- `TARGET`: path to the local source file or module to baseline.21- `LANGUAGE`: the target's language (e.g., `python`, `rust`, `typescript`). Required to select correct invariant patterns.2223## Procedure24251. **Validate the request.** Confirm `TARGET` is a concrete, scoped implementation task with a named local path. If `TARGET` is absent, empty, or points to a non-local artifact, raise `BLOCKED-INPUT` and stop. **Done when:** `TARGET` is confirmed as a concrete local path.262. **Enumerate invariants.** For `LANGUAGE`, enumerate the language-native invariant patterns that govern correctness: type contracts, ownership/borrow rules, null/void guards, resource lifecycle ordering, and domain-specific preconditions. Write each as a named, executable check with a unique identifier. **Done when:** every invariant pattern is a named, executable check with a unique identifier.273. **Insert fail-fast guards.** Before every mutable state operation, every external call, and every branching decision, insert the matching invariant check. If any check fails, halt immediately with `INVARIANT-FAIL: <identifier>` and the observed violation. The target artifact is unchanged until all checks pass. **Done when:** every mutable state operation, external call, and branching decision has a matching invariant guard.284. **Eliminate special cases.** Scan the target for:29 - Boolean flag arguments or module-level toggles that gate behavior.30 - Hardcoded branch paths that duplicate a general case.31 - Numeric or string domain constants used as inline guards.32 For each found artifact, either refactor the boolean branch into a data-driven lookup, merge the special case into the general path, or convert the magic constant into a named constant with a documented invariant. **Done when:** no boolean flags, hardcoded duplicate branches, or inline magic constants remain.335. **Re-validate.** Run checks by compiling the target in its language-native build and running the existing test suite scoped to the target. If the project has no compile step, run the test suite alone. If any check fails, halt with `INVARIANT-FAIL: <identifier>` listing the specific failure. Record the complete set of removed special-case artifacts as the resolution log. **Done when:** all invariant checks pass and the resolution log is complete.3435## Failure and recovery36| Failure class | Condition | Result |37|---|---|---|38| BLOCKED-INPUT | `TARGET` absent, empty, or non-local | Stop. No file changed. |39| INVARIANT-FAIL | A named invariant check fails | Stop. Artifact unchanged. Report `<identifier>`. |40| SPECIAL-CASE-INCOMPLETE | Not all special-case artifacts resolved | Stop. Report the unresolved set. |4142Partial-result rule: in-place edits to the target are rolled back via VCS on failure. Run `git restore TARGET` to revert the working copy to its pre-edit state. If the target was a new file, delete it instead. No partial result is emitted.4344## Output45The target local artifact replaced with its invariant-first refinement, plus a resolution log listing every removed special case and the invariant identifier that now governs its behavior.
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