---
title: "wasi-test-fixtures — Mova code model"
description: "Mova code model of wasi-host/src/tests.rs: components with their labels, obernants and the model text."
url: "https://groupants.elamur.ai/free/en/mova/wasi-host/src/tests.rs.groupant/wasi-test-fixtures.groupant/"
---
Elamur: [Mova](https://md.mova.elamur.ai/free/en/) · [Dictionary](https://md.dictionary.elamur.ai/free/en/) · [Research](https://md.research.elamur.ai/free/en/) · **Groupants**

This page as HTML: <https://groupants.elamur.ai/free/en/mova/wasi-host/src/tests.rs.groupant/wasi-test-fixtures.groupant/>

# wasi-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

- **kind:** groupant_fragment
- **status:** partial source bound model
- **source:** [`wasi-host/src/tests.rs`](https://github.com/ElamurAI/mova-free/blob/main/wasi-host/src/tests.rs)
- **source SHA-256:** `74685e5440b3b7df…`
- **covers:** 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. (bytes 105–768)
- **part of:** [wasi-memory-tests](https://md.groupants.elamur.ai/free/en/mova/wasi-host/src/tests.rs.groupant/)
- **repository folder:** [`wasi-host/src/tests.rs.groupant/wasi-test-fixtures.groupant`](https://github.com/ElamurAI/mova-free/tree/main/wasi-host/src/tests.rs.groupant/wasi-test-fixtures.groupant)
- **repository commit:** `855da7bd4a7b`

> **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](#approximant) |
| **ast** | partial | `../syntax.json` |
| **cost** | symbolic source derived | [invariant](#invariant) |
| **descriptant** | present | [descriptant](#descriptant) |
| **invariant** | partial | [invariant](#invariant) |
| **tests** | executed bounded checks | [tests](#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](#behavior-complement) |
| `reverse_reconstruction` | reverse_reconstruction | partial source derived model | [reverse_reconstruction](#reverse-reconstruction) |
| `fixture_contents` | fixture_contents | partial source derived model | [fixture_contents](#fixture-contents) |
| `pointer_assumption` | pointer_assumption | partial source derived model | [pointer_assumption](#pointer-assumption) |
| `root_adapter` | root_adapter | partial source derived model | [root_adapter](#root-adapter) |
| `error_propagation` | error_propagation | partial source derived model | [error_propagation](#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.