Changelog of @hackage/nova-nix 0.1.0.0

Changelog

Cross-platform ATerm serialization: storePathToText always uses / for store paths regardless of OS, parseStorePath accepts both / and \
Builder inherits system environment, overlays build env via Map.union — fixes silent process failures on Windows (missing SYSTEMROOT)
Builder PATH derived from builder location (buildPath) — includes builder dir and MSYS2 sibling usr/bin for coreutils discovery
findTestShell prefers known Git for Windows bash over WSL launcher (System32\bash.exe)
Parser strips UTF-8 BOM — Windows editors (Notepad, PowerShell) commonly add byte order marks
Demo test.nix included: derivations, lambdas, builtins.map, arithmetic — runs on all platforms
16 builtins exposed at top level without builtins. prefix (toString, map, throw, import, derivation, abort, baseNameOf, dirOf, isNull, removeAttrs, placeholder, scopedImport, fetchTarball, fetchGit, fetchurl, toFile) — matches real Nix language spec, required for nixpkgs compatibility

String context tracking on all VStr values: SCPlain, SCDrvOutput, SCAllOutputs
Context propagation through interpolation, string concatenation, replaceStrings, substring, concatStringsSep, and all string builtins
Nix.Eval.Context module: pure helpers for context construction, queries, and extraction
derivation builtin now collects string contexts into drvInputDrvs and drvInputSrcs
New builtins: hasContext, getContext, appendContext
Nix.DependencyGraph: BFS graph construction with Data.Sequence (O(V+E)), topological sort via Kahn's algorithm, cycle detection
Nix.Substituter: full HTTP binary cache protocol — narinfo fetch/parse, Ed25519 signature verification, NAR download/decompress/unpack, store DB registration, priority-ordered multi-cache
Nix.Builder.buildWithDeps: recursive dependency resolution — topo sort, cache check, binary substitution, local build fallback
CLI nova-nix build now builds full dependency trees, not just single derivations
Cleanup pass: eliminated all partial functions (T.head/T.tail to T.uncons, !! to safe lookup, last to pattern match), flattened deeply nested code into composed functions, Data.Sequence BFS queues throughout, semantic section organization
494 tests (68 new: string context, context propagation, dependency graph, substituter, build orchestrator)

Real SQLite-backed store database (ValidPaths + Refs tables, WAL mode)
Store operations: addToStore (cross-device safe), scanReferences (byte-scan for store path references), setReadOnly (recursive), writeDrv
parseStorePath: parse full store path strings into StorePath values
ATerm parser (fromATerm): hand-rolled recursive descent, full round-trip with toATerm
builtinDerivation now populates drvOutputs with DerivationOutput records
Full buildDerivation loop: input validation, temp directory setup, environment construction, process execution via System.Process, reference scanning, output registration in store DB
CLI nova-nix build FILE.nix: evaluate, extract derivation, write .drv, build, print output path
426 tests (45 new: 10 store DB, 13 store ops, 10 ATerm parser, 8 builder, 4 CLI end-to-end)

Full Nix expression parser (hand-rolled recursive descent, 13 precedence levels)
Lazy evaluator with thunk-based evaluation, knot-tying for recursive bindings
85 builtins: type checks, arithmetic, bitwise, strings, lists, attrsets, higher-order, JSON, hashing, version parsing, tryEval, deepSeq, genericClosure, all IO builtins, derivation
MonadEval typeclass — evaluator is polymorphic in its effect monad (PureEval for tests, EvalIO for real evaluation)
IO builtins: import, readFile, pathExists, readDir, getEnv, toPath, toFile, findFile, scopedImport, fetchurl, fetchTarball, fetchGit, currentTime
derivation builtin: attrset to .drv build recipe with computed drvPath and outPath
ATerm serialization with string escaping, sorted environments
placeholder and storePath builtins via nova-cache hashing
Content-addressed store path types with Windows/Unix support
Derivation types, platform detection, and textToPlatform/platformToText
Shared hash utilities in Nix.Hash (SHA-256 hex, truncated base-32, byteToHex)
CLI: nova-nix eval FILE.nix evaluates a .nix file and prints the result
381 tests, zero framework dependencies
CI pipeline: HLint, Ormolu, build with -Werror, test, Hackage publish on tags

Total functions only — no read, head, tail, !!, fromJust, or Map.!
Argument injection prevention in fetch builtins (-- separator before user URLs)
Path traversal validation in writeToStore (rejects /, .., null bytes)
Content-hashed temp directories for fetchGit (no predictable paths)
Store paths set read-only after registration (immutability enforcement)