slop-guard
Skill1 starsChanged 45 days agoMITView on GitHub
Write-time patterns that reject low-evidence TypeScript and JavaScript: fake types (unknown contracts, chained or widen-then-assert casts), wasteful array and reducer passes, module mocking, and reflection. Use before writing or editing any code file; the type rules are for .ts, .tsx, .js, .jsx, .mjs, and .cjs. Adds no dependency or lint config; applies to new and changed lines only.
1 other project uses a version of this.
Adopted by
Most recently taken up by
- kleosr/kleosrulesword for word, first seen Sep 29, 2026
Other versions1 project uses a version of this.
Word for word · 1
- kleosr/kleosrules★ 1100% same
Edited · 0
None found.
Wrote their own version · 0
None found.
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository13 other files it gives its agents.
- AGENTS.mdAGENTS.md
- asd-ste100Skill
- auth-boundariesSkill
- bridle-harnessSkill
- code-architectureSkill
- cqrs-data-flowSkill
- debuggingSkill
- handoffSkill
- live-ui-syncSkill
- production-readinessSkill
- prompt-briefSkill
- system-designSkill
- testingSkill
The file
We split this skill into the rules it gives an agent
2 rules. About 0 are common, 0 are distinctive, and 2 are very specific to this project.
≈0
Common · estimate
Many files like this have a rule of this kind.
≈0
Distinctive · estimate
This author's own choices. Worth a look.
2
Very specific
Tied to their project's names, files or tools. Probably skip.
- Common
- Distinctive
- Very specific
- Very specific: line 34
Do one pass, not .filter(...).map(...).
- Very specific: line 40
Do not call vi.mock, jest.mock, doMock, or unstable_mockModule.
≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.
Files
Slop guard
Low-evidence code claims a type or a behavior that nothing proves. Write the proof into the code, at the boundary where the data enters. Apply this to the lines you write or change. Do not migrate old code unless the ask says so. In other languages, apply the same idea: parse at the boundary, keep data passes linear, and test through real seams.
Types carry evidence
| Do | Do not |
| Parse input once at the boundary (schema, type guard, or explicit checks), then pass the narrow type. | Accept unknown (or a union with it) as a function parameter. The cause of an error and the subject of a type predicate are the exceptions. |
| Return the real type. | Declare a return of unknown, Promise<unknown>, or an alias that resolves to unknown. |
Give a dictionary a real value type: Record<UserId, User>, Map<string, Order>. | Use Record<string, unknown>, any, object, or {} as a value contract. A generic constraint like T extends Record<string, unknown> is allowed. |
| Keep a known value at its known type. | Pass a known value into an unknown, object, or open-dictionary slot, then assert it back. |
| Cast only when a check in the same flow proves the type. Put that proof in code, not in a comment. | Chain assertions (x as unknown as T, <T><unknown>x). as const is allowed. |
| Narrow with a parser or a type predicate at the boundary. | Scatter ad hoc typeof x === "..." checks through business code. typeof x === "undefined" probes are allowed. |
| Call functions and read properties through their types. | Use Reflect.apply or Reflect.get to skip the type system. |
Name the domain thing: User, OrderLine. | Put Shape in a local symbol name (UserShape). A library member such as schema.shape is allowed. |
Data passes stay linear
- Do one pass, not
.filter(...).map(...). UseflatMap, a loop, or lazy.values().filter(...).map(...).toArray()when the runtime supports iterator helpers. Keep callback order, indexes, andthisArgsemantics the same. - In
reduce, mutate a fresh local accumulator. Do not copy it on every step with spread,Object.assign({}, acc, ...),Array.from(acc),concat, orslice. - To omit an optional field, build the object with an
if. Do not use...(cond ? { a } : {}): omitting a key and setting it toundefinedare different.
Tests use real seams
Do not call vi.mock, jest.mock, doMock, or unstable_mockModule. Pass the dependency in (parameter, constructor, or layer) and give the test a real or in-memory implementation.
Effect
Apply this section only when the owning package manifest declares effect.
- Match tagged values with
Match,Predicate.isTagged, or tagged-enum matching. Do not compare or switch on_tagby hand, including insideEffect.catchhandlers. - Build tagged values with Schema, a tagged class or error, or
Data.taggedEnum. Do not write{ _tag: "..." }literals. - Runtime callers import the owning Layer and yield the service. Do not import
make<Service>constructors from project modules outside tests. - Replace chained literal ternaries over one value with
Match.
Source
Adapted from the rule set of dmmulroy/anti-slop (MIT) at c44ef22. To enforce these rules with Oxlint in a repo, install that project's install-anti-slop skill. Adding the dependency needs approval.
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