gen.anything / gen.json: arbitrary Nix values #12

New issue

Closed

opened 2026-09-13 21:24:23 +09:00 by natsukium · 1 comment

natsukium commented

2026-09-13 21:24:23 +09:00

Owner

Missing

gen.anything (an arbitrary Nix value: null, bool, int, float, string, list, attrset, recursively) and gen.json (the same without null-free restrictions and with JSON-safe floats).

Why

fast-check has fc.anything / fc.json; Hypothesis builds the same with st.recursive. Properties over nixpkgs lib functions (lib.isType, toJSON round trips, recursiveUpdate, ...) need "any value" and every example in examples/nixpkgs-lib-*.nix currently assembles a subset by hand.

Suggested shape

Built on gen.recursive (#5) and gen.attrsOf (#4); doubles as the dogfood test for both.
Options to exclude floats or functions, and to cap depth via size.
examples/nixpkgs-lib-comprehensive.nix should be checked for hand-rolled equivalents to replace.

## Missing `gen.anything` (an arbitrary Nix value: null, bool, int, float, string, list, attrset, recursively) and `gen.json` (the same without `null`-free restrictions and with JSON-safe floats). ## Why fast-check has `fc.anything` / `fc.json`; Hypothesis builds the same with `st.recursive`. Properties over nixpkgs `lib` functions (`lib.isType`, `toJSON` round trips, `recursiveUpdate`, ...) need "any value" and every example in `examples/nixpkgs-lib-*.nix` currently assembles a subset by hand. ## Suggested shape - Built on `gen.recursive` (#5) and `gen.attrsOf` (#4); doubles as the dogfood test for both. - Options to exclude floats or functions, and to cap depth via size. - `examples/nixpkgs-lib-comprehensive.nix` should be checked for hand-rolled equivalents to replace.

natsukium referenced this issue

2026-09-13 21:24:52 +09:00

gen.sized / gen.recursive: size-driven depth for recursive generators #5

natsukium referenced this issue

2026-09-14 00:44:13 +09:00

gen.int: span overflow on full-width ranges #16

natsukium commented

2026-09-14 00:44:14 +09:00

Author

Owner

Implemented in d153fd0, pushed to main.

Implemented in d153fd0, pushed to main.