Elamur Groupantswasi-test-fixtures
The groupant beside wasi-host/src/tests.rs in the Mova repository: what the code computes, what it never does, how to go back from its outputs, its invariants, cost and checks.
Facts
Implementation material. A Mova code model describes this code at one source revision: partial models, finite checks and their stated scope. It is not a reviewed general exposition, and its labels are shown as written, never raised.
Components
| component | label | where |
|---|---|---|
| approximant | partial | approximant |
| ast | partial | ../syntax.json |
| cost | symbolic source derived | invariant |
| descriptant | present | descriptant |
| invariant | partial | invariant |
| tests | executed bounded checks | tests |
Obernants
The typed relations around the forward model: the behaviour complement (what the code never does), the reverse reconstruction (every input compatible with an output) and specialised views.
| id | type | label | where |
|---|---|---|---|
behavior_complement | behavior_complement | partial source derived model | behavior_complement |
reverse_reconstruction | reverse_reconstruction | partial source derived model | reverse_reconstruction |
fixture_contents | fixture_contents | partial source derived model | fixture_contents |
pointer_assumption | pointer_assumption | partial source derived model | pointer_assumption |
root_adapter | root_adapter | partial source derived model | root_adapter |
error_propagation | error_propagation | partial source derived model | error_propagation |
Model text
descriptant
wasi-test-fixtures
ctx creates /d, two files and argv prog,arg1; put_str raw-copies at given coordinate; open writes path at1000 and invokes production path_open with root fd3/follow1 and output900.
Epoch 2026-10-31
Prospective review recorded before edits. Source review found late output FAULT effects and weaker-than-capability rights metadata; these are modeled as current behavior rather than silently repaired. Only bounded new test blocks were added; production code remains unchanged. Actual finite results and exact restoration receipts live under $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. No full mlab guest, frozen suite, GPU or corpus run. This node retains its scoped observations for future refinement.
approximant
Forward relation
ctx creates /d, two files and argv prog,arg1; put_str raw-copies at given coordinate; open writes path at1000 and invokes production path_open with root fd3/follow1 and output900.
Scope: wasi-test-fixtures. State and transitions follow the authoritative source, including partial effects before errors. No executable approximate replacement is attached: categorical errno/effects and module execution lack a useful validated percentage metric; future numerical profiles may only use1/2/5/10% caps after domain/reference evidence.
invariant
Invariant and cost
ctx creates /d, two files and argv prog,arg1; put_str raw-copies at given coordinate; open writes path at1000 and invokes production path_open with root fd3/follow1 and output900.
The invariant is conditional on the admitted transition: Successful helper open cannot return an fd unrelated to output word900; bounded helper does not perform host directory IO.
Cost: O(path+file bytes) tiny fixture; helper raw slices require bounds as caller premise.
No wall-time gain, universal resource bound or atomic rollback is inferred. External Vfs/wasmi/native-mlab work remains separately charged.
models
Typed model catalog
behavior_complement
Subject: wasi-host/src/tests.rs at SHA-256 74685e5440b3b7df7f40518395e62d6cd68a60e80ff71e87b772f020c80bec8d, scope wasi-test-fixtures. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: Successful helper open cannot return an fd unrelated to output word900; bounded helper does not perform host directory IO.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
reverse_reconstruction
Subject: wasi-host/src/tests.rs at SHA-256 74685e5440b3b7df7f40518395e62d6cd68a60e80ff71e87b772f020c80bec8d, scope wasi-test-fixtures. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: fd result determines produced word at900 on success, not path or prior descriptor state; test helper inputs are fixture-defined.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
fixture_contents
Subject: wasi-host/src/tests.rs at SHA-256 74685e5440b3b7df7f40518395e62d6cd68a60e80ff71e87b772f020c80bec8d, scope wasi-test-fixtures. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: a.txt=hello world,b.txt empty; argv nul size10. This is known test data, not arbitrary external files.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
pointer_assumption
Subject: wasi-host/src/tests.rs at SHA-256 74685e5440b3b7df7f40518395e62d6cd68a60e80ff71e87b772f020c80bec8d, scope wasi-test-fixtures. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: put_str uses unchecked slice indexing and can panic unlike production get_str; test input lengths ensure bounds.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
root_adapter
Subject: wasi-host/src/tests.rs at SHA-256 74685e5440b3b7df7f40518395e62d6cd68a60e80ff71e87b772f020c80bec8d, scope wasi-test-fixtures. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: open passes root3 and follow1, so does not cover every dirfd/follow combination.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
error_propagation
Subject: wasi-host/src/tests.rs at SHA-256 74685e5440b3b7df7f40518395e62d6cd68a60e80ff71e87b772f020c80bec8d, scope wasi-test-fixtures. Domain: the source transition and bounded fixtures described in approximant.md; readable valid host resources where required. Observation: returned values, byte coordinates, state/effect order, not total-system semantics. Operator/relation: path_open error propagated before get_u32 output; successful helper reads exact fd from memory.
Status: partial source-derived relation; complement is a scoped exclusion hypothesis, reverse preserves all compatible antecedents described rather than a chosen inverse. Assumptions: production branch order, declared coordinate/resource premises; no completeness claim for untested inputs. Evidence: tests.md distinguishes actual execution from source review; finite observations can falsify but not prove the relation.
tests
Checks and limits
Named actual-source tests run twice per debug/release; exact commands and numeric statuses retained externally. Test success is finite evidence only.
Exact names: tests::args_and_prestat, tests::open_read_seek_write.
Memory tests bypass linker ABI; tiny empty/unreachable guests exercise engine outcomes only. The CLI test uses isolated import/export/journal fixtures.
Five compiled production/helper-source controls: append offset, virtual clock advance, trap status, CLI export gate and newest-mtime max. Each compiles, fails its selected assertion, restores exact original bytes and passes again. These controls cover their target relations, not every node. No assertion-only mutants. See external source-test-map.json, native-commands.json, verify.rs and numeric/raw receipts in $MOVA_DATA/runs/octopus-wave31-wasi-2026-10-31. The example main and frozen mlab paths are never executed.
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