Changelog

All notable changes to this project will be documented in this file.

[Unreleased]

Added

• Expanded Malli admission to cover :and, :tuple, :vector, :sequential, :set (with :min/:max parsed and dropped), :map with required keys, {:optional true} keys, and the :closed true property (default is open, matching Malli's semantics — extra keyword keys are admitted with Any values); multi-arity :function with per-arm FnMethodT; :multi with {:dispatch :kw} tagged dispatch (later branches are narrowed by negation of earlier tags); :=; :schema with optional {:registry {...}} properties carrying a local registry; :ref resolved through the active registry with cycle detection (recursive positions emit InfCycleT rather than diverging); and the primitive leaves :double, :float, :qualified-keyword, and :qualified-symbol. Sequence/regex combinators outside the :=> head remain experimental.
• ClojureScript source-file support (experimental, opt-in via --cljs-enable). Skeptic discovers .cljs and .cljc files in deps.edn, Leiningen, and Shadow-CLJS projects and admits Plumatic Schema (s/defn / s/def / s/defschema) and Malli (:malli/schema) declarations on cljs vars. .cljc files are admitted twice (once per host language); identical findings from both passes are deduped with lang set to ["clj","cljs"].
• clj -T:skeptic check deps.edn tool entrypoint, so Skeptic is now usable from a deps.edn :tools/usage alias in addition to the Leiningen plugin. Supported tool arg-map keys include :project-dir, :paths (override discovered source paths), and :alias (merge additional deps.edn aliases when resolving the project's basis). clojure -M:skeptic and clj -X:skeptic print a message redirecting to the -T form.
• Analysis now runs against the project's own classpath: the project's pinned versions of Clojure, Plumatic Schema, Malli, tools.analyzer, and any other library are what drive checking. Skeptic's own declared dependency versions no longer collide with the project's.
• --plumatic-disable and --malli-disable flags to switch off either intake stream entirely. A disabled stream contributes no entries and no findings whose source matches that stream. --plumatic-disable additionally suppresses :skeptic/type-overrides, since overrides are a Plumatic-domain construct. A Var declared via both streams is still admitted via the enabled one; combining both flags leaves only Skeptic's built-in native-fn declarations.
• lang field on every JSONL location object identifying the host language the reported type was admitted under: "clj", "cljs", or a sorted JSON array ["clj","cljs"] when both passes of a .cljc file produced the same finding.
• Function values are now checked against Java callable-interface targets (Runnable, Callable, Comparator, and the java.util.function.* single-abstract-method interfaces). Previously a :- Runnable parameter produced a confusing (=> Any) but expected java.lang.Runnable mismatch for any Clojure fn; now Skeptic checks the source fn's arity against the interface's abstract-method arity and casts its declared return type to Bool for Predicate / BiPredicate, Int for Comparator, and Dyn for the rest.

Fixed

• Plumatic Schema map schemas using non-keyword required keys (e.g. {(s/required-key "a") s/Int}) now check correctly: correct call sites are no longer flagged with a spurious unexpected-key finding, and missing-required-key cases are now reported instead of being silently dropped. Keyword required keys were already handled by Plumatic's short-circuit to bare keywords; the bug only affected string and other non-keyword keys.
• Analysis no longer throws Expected typed entry on Malli :map or other unsupported Malli forms encountered while building the per-namespace declaration dict.
• (assoc nilable-map k v) (and update on a nilable map) no longer carries a Maybe wrapper through the result, since (assoc nil k v) returns {k v} — not nil. The nil-branch is captured by downgrading the inner map's required keys to optional, so callers that previously saw a spurious nullability finding now get a clean check, while callers that depended on inner keys being required see a :map-nullable-key finding instead of a false pass.
• (when (or (nil? a) (nil? b) ...) (throw ...)) now narrows every guarded local in subsequent statements, not just the single-variable shape. Previously a disjunctive throw-guard's De-Morgan negation was treated as unsupported, so the rest of the enclosing do continued to see each local as (maybe T) — yielding a spurious nullability finding on a correct program. The conjunctive shape (when (and (nil? a) (nil? b)) (throw)) was already handled and is unchanged.

[0.8.1] - 2026-05-05

Added

• Per-namespace error counts at the end of text and JSONL reports, so large runs show which namespaces are worst-offending without piping through wc.

Fixed

• Collections that mix a fixed prefix with a homogeneous tail (e.g. [(s/one s/Int 'a) (s/one s/Str 'b) s/Keyword]) are now checked correctly. Previously Skeptic treated every collection schema as either fully fixed-arity or fully homogeneous (#8).
• Earlier cond / case branches now restrict later ones. A predicate test that succeeds on one arm narrows the remaining arms by negation, so a (some? v) arm following (vector? v) sees v as a non-vector non-nil, and downstream sum-type variants flagged exhausted are removed from the residual (#9).

[0.8.0] - 2026-05-03

Added

• Initial Malli intake. Skeptic now reads :malli/schema Var metadata and projects the compile-time (malli.core/function-schemas) registry (which captures m/=>). The first batch of admitted forms covers single-arity [:=> [:cat ...] out] function schemas, :maybe, :or, :enum, the primitive leaves :int, :string, :keyword, :symbol, :boolean, :nil, and :any, and the bare predicate symbols recognized by Skeptic's predicate registry. Unsupported Malli forms admit as dynamic. Broader Malli shapes are added in subsequent releases.
• --explain-full flag to print fully expanded structural forms in type-mismatch output. Without the flag, declared Schema names are preferred so reports stay compact.
• Findings carry source attribution. Text output annotates each location with [source: schema|malli|native|type-override|inferred] and JSONL findings include the same source on the location object, so consumers can tell which intake stream produced the expected type. The corresponding Provenance is recorded on every admitted Type and is used to render the :source field.

Changed

• Default type rendering uses declared Schema and Malli names where available, falling back to fully expanded structural forms only when pinned via --explain-full. Reports for s/maybe, s/eq, declared map schemas, and similar shapes are noticeably shorter.
• lein skeptic runs the analysis pass under schema.core/without-fn-validation, avoiding Plumatic Schema function-validation overhead in projects that have runtime Schema validation enabled. Runtime validation is restored after Skeptic's pass completes.

Fixed

• Multi-arity defn output is now checked per arity against the declared return type for that specific arity, instead of comparing every analyzed method against the first arity's declared output.
• Flow-sensitive narrowing flows through more shapes: aliases, let-bound vars, path-shaped map projections, conditional branches, and enum/sum-type tests. A (some? n) or (string? s) guard now refines the local in subsequent expressions even when the local reaches the test through a structured-origin path.
• Conditional narrowing fixes for let-vars and and/or paths so branch tests on a let-bound local refine subsequent reads of that local (previously the refinement was lost across the let boundary).
• Dynamic types narrow through ground-classifying positive predicates (string?, int?, keyword?, etc.), so a Dyn value tested positively against a recognized predicate is treated as the corresponding ground type for the remainder of the then-branch.

[0.7.1] - 2026-04-22

Added

• -o/--output OUTPUT_FILE on lein skeptic so skeptic's findings, summary, or JSONL stream can be written to a file while lein/JVM chatter stays on stdout (#2).

Changed

Fixed

• (or x fallback) no longer reports a spurious nullability error when fallback is truthy.
• Flow-sensitive narrowing now flows through named destructured map keys: a (str/blank? a) or (some? a) guard on a {:keys [a]} destructure refines the local a itself, not only the parent map, so downstream reads of a see the narrowed type.

[0.7.0] - 2026-04-19

Added

• Clojars coordinates org.clojars.nomicflux/skeptic and org.clojars.nomicflux/lein-skeptic, :deploy-repositories for Leiningen, CI checks that keep the library and plugin versions aligned before publish, and GitHub Actions for Release lifecycle (orchestrates phases), Change project versions (reusable version bump), and Publish to Clojars (reusable deploy to Clojars).
• GitHub Actions CI running automated checks on pushes and pull requests.
• lein skeptic -p / --porcelain for newline-delimited JSON output (one JSON object per line), documented in the README.
• lein skeptic --profile for optional CPU, memory, and wall-clock profiling; when combined with --porcelain, the profile summary is written to stderr so stdout stays JSONL-only.
• Optional project .skeptic/config.edn with :exclude-files (root-relative globs that skip loading and checking matched paths) and :type-overrides (Plumatic Schema forms evaluated with schema.core in scope and merged into collected declarations, including :output-only overrides).
• Fine-grained check controls: :skeptic/ignore-body and :skeptic/opaque on s/defn attribute maps, and ^{:skeptic/type T} on expressions (see README Suppressing checks).
• An expanded user-facing README.md that explains what Skeptic checks, how the plugin works, how to install it, how to interpret its reports, where to find the algorithm reference, and how to use configuration, JSONL output, suppressions, and a short “building from source” section.
• A new --analyzer CLI flag to print analyzer output while inspecting a namespace.
• Richer mismatch reports with source expressions, file and line information, enclosing forms, and affected inputs.
• Output validation for function bodies, so Skeptic now checks declared return Plumatic Schema annotations in addition to call-site argument compatibility.
• Static-call coverage and tests for Plumatic-Schema-sensitive operations such as get and merge.

Changed

• Reworked the checker to analyze forms through clojure.tools.analyzer ASTs instead of the older macroexpansion-driven pipeline.
• Switched mismatch checking to a directional cast engine that reports cast rules, blame side, and blame polarity instead of only undirected mismatch against declared Plumatic Schema annotations.
• Switched namespace reading to clojure.tools.reader with source logging so reports can preserve source text and location metadata.
• Canonicalized Plumatic Schema handling across checker internals so built-in classes, Plumatic Schema aliases, map keys, and maybe types compare more consistently.
• Expanded namespace declaration collection to inspect schematized interned vars instead of only public vars.
• Further refactored analysis and the per-namespace checking pipeline, with continued improvements to the directional cast and blame reporting model (theory from Ahmed, Findler, Siek, and Wadler, Blame for All, POPL 2011; see README).
• Leiningen plugin uses an explicit Skeptic dependency profile so classpath wiring for the library stays clear.

Fixed

• Preserved auto-resolved keywords from the target namespace when collecting declared Plumatic Schema annotations and checking forms.
• Reduced nested helper calls and map lookups to their final inferred types before reporting mismatches.
• Improved output mismatch rendering for declared map Plumatic Schema annotations so reported types are canonical and easier to read.
• Stabilized self-analysis and internal checking so recursive or self-hosted runs no longer depend on loader-sensitive semantic values embedded in canonical analysis data.
• Leiningen now surfaces a non-zero exit when Skeptic reports inconsistencies instead of treating the run as successful in some failure cases.
• Broader inference and checking fixes: flow-sensitive nil narrowing around throw, case, and cond; numeric tower comparisons; clojure.string/blank?; conditional branches; maybe / eq / nil edge cases; invoke analysis without redundant walks; cyclic type graphs; preservation of map projections through checks; and a single consolidated boundary for schema-side compatibility checks against inferred types.