mlua_lshape/
lib.rs

1//! mlua-lshape — mlua wrapper for `lshape` (Pure Lua Schema-as-Data
2//! validator + LuaCATS codegen).
3//!
4//! The five `lshape/*.lua` sources are vendored under `lua/lshape/` and
5//! embedded into the binary via [`include_str!`] at compile time, so
6//! downstream crates get the full module tree without any runtime
7//! filesystem dependency.
8//!
9//! Typical use from Rust:
10//!
11//! ```no_run
12//! use mlua::Lua;
13//! use mlua_lshape::install;
14//!
15//! let lua = Lua::new();
16//! install(&lua).unwrap();
17//! let chunk = r#"
18//!     local lshape = require("lshape")
19//!     local T = lshape.t
20//!     local Voted = T.shape({ answer = T.string })
21//!     local ok, why = lshape.check.check({ answer = "42" }, Voted)
22//!     assert(ok, why)
23//! "#;
24//! lua.load(chunk).exec().unwrap();
25//! ```
26
27use mlua::{Lua, Result, Table, Value};
28
29/// Embedded Lua source files. Key is the `require` path (e.g. `"lshape"`
30/// → `lua/lshape/init.lua`), value is the file contents.
31///
32/// Kept `pub` so downstream crates can embed the same sources (e.g. to
33/// inject them into a non-mlua Lua VM or to hash them for drift checks).
34pub const LSHAPE_SOURCES: &[(&str, &str)] = &[
35    ("lshape",         include_str!("../lua/lshape/init.lua")),
36    ("lshape.t",       include_str!("../lua/lshape/t.lua")),
37    ("lshape.check",   include_str!("../lua/lshape/check.lua")),
38    ("lshape.reflect", include_str!("../lua/lshape/reflect.lua")),
39    ("lshape.luacats", include_str!("../lua/lshape/luacats.lua")),
40];
41
42/// Install the `lshape.*` modules into the given Lua state's
43/// `package.preload` table. After this returns, Lua code can
44/// `require("lshape")` / `require("lshape.t")` / etc. normally.
45///
46/// This does **not** call `require` itself; modules stay lazy until the
47/// host Lua code pulls them in.
48pub fn install(lua: &Lua) -> Result<()> {
49    let package: Table = lua.globals().get("package")?;
50    let preload: Table = package.get("preload")?;
51
52    for (name, src) in LSHAPE_SOURCES {
53        let name_owned = (*name).to_owned();
54        let src_owned = (*src).to_owned();
55        let loader = lua.create_function(move |lua, ()| -> Result<Value> {
56            let chunk = lua
57                .load(&src_owned)
58                .set_name(&format!("@{}", name_owned));
59            chunk.eval::<Value>()
60        })?;
61        preload.set(*name, loader)?;
62    }
63
64    Ok(())
65}
66
67#[cfg(test)]
68mod tests {
69    use super::*;
70
71    #[test]
72    fn install_and_require_lshape() {
73        let lua = Lua::new();
74        install(&lua).unwrap();
75        lua.load(
76            r#"
77            local lshape = require("lshape")
78            assert(type(lshape) == "table")
79            assert(type(lshape.t) == "table")
80            assert(type(lshape.check) == "table")
81            assert(type(lshape.reflect) == "table")
82            assert(type(lshape.luacats) == "table")
83            "#,
84        )
85        .exec()
86        .unwrap();
87    }
88
89    #[test]
90    fn check_validates_shape() {
91        let lua = Lua::new();
92        install(&lua).unwrap();
93        lua.load(
94            r#"
95            local lshape = require("lshape")
96            local T = lshape.t
97            local Voted = T.shape({ answer = T.string })
98            local ok, _ = lshape.check.check({ answer = "42" }, Voted)
99            assert(ok)
100            local ok2, why = lshape.check.check({ answer = 42 }, Voted)
101            assert(not ok2)
102            assert(why:find("shape violation"))
103            "#,
104        )
105        .exec()
106        .unwrap();
107    }
108
109    #[test]
110    fn vendored_version_matches() {
111        let lua = Lua::new();
112        install(&lua).unwrap();
113        lua.load(
114            r#"
115            local lshape = require("lshape")
116            assert(lshape._VERSION == "0.1.0",
117                "expected lshape._VERSION == '0.1.0', got " .. tostring(lshape._VERSION))
118
119            local T = lshape.t
120            -- v0.1.0 surface smoke: any_of, pattern, partial, literal
121            local U = T.any_of({ T.string, T.number })
122            assert(lshape.check.check("x", U))
123            assert(lshape.check.check(1, U))
124            assert(not (lshape.check.check(true, U)))
125
126            local Slug = T.pattern("^[a-z]+$")
127            assert(lshape.check.check("abc", Slug))
128            assert(not (lshape.check.check("ABC", Slug)))
129
130            local P = T.partial({ a = T.string, b = T.number })
131            assert(lshape.check.check({}, P))
132            assert(lshape.check.check({ a = "x" }, P))
133
134            local L = T.literal("yes")
135            assert(lshape.check.check("yes", L))
136            assert(not (lshape.check.check("no", L)))
137            "#,
138        )
139        .exec()
140        .unwrap();
141    }
142}
mlua_lshape/lib.rs

mlua_lshape/
lib.rs
