alef 0.97.1

Opinionated polyglot binding generator for Rust libraries
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168

use super::Pyo3Backend;
use crate::core::backend::Backend;
use crate::core::config::{ResolvedCrateConfig, new_config::NewAlefConfig};
use crate::core::ir::{ApiSurface, EnumDef, EnumVariant, FieldDef, TypeDef, TypeRef};
use std::path::Path;

const CORE_SOURCE: &str = r#"
#[derive(Clone, Default, serde::Serialize, serde::Deserialize)]
pub enum Policy {
    #[default]
    None,
    Analyze { label: String },
}
#[derive(Clone, Default, serde::Serialize, serde::Deserialize)]
pub struct Request { pub policy: Policy }
#[derive(Clone, Default, serde::Serialize, serde::Deserialize)]
pub struct Prepared { pub request: Request }
#[derive(Clone, Default, serde::Serialize, serde::Deserialize)]
pub struct Batch { pub items: Vec<Prepared> }
"#;

const ROUND_TRIP_TEST: &str = r#"
#[test]
fn nested_enum_payload_survives_core_to_binding_and_serde_round_trips() {
    let expected = serde_json::json!({"items": [
        {"request": {"policy": {"Analyze": {"label": "retain me"}}}}
    ]});
    let core: test_lib::Batch = serde_json::from_value(expected.clone()).unwrap();
    let binding: Batch = core.into();
    assert_eq!(serde_json::to_value(&binding).unwrap(), expected);
    let restored: Batch = serde_json::from_value(expected.clone()).unwrap();
    assert_eq!(serde_json::to_value(restored).unwrap(), expected);
}
"#;

fn record(name: &str, field: &str, ty: TypeRef) -> TypeDef {
    TypeDef {
        name: name.into(),
        rust_path: format!("test_lib::{name}"),
        has_serde: true,
        has_default: true,
        fields: vec![FieldDef {
            name: field.into(),
            ty,
            ..Default::default()
        }],
        ..Default::default()
    }
}

fn api_surface() -> ApiSurface {
    ApiSurface {
        crate_name: "test-lib".into(),
        version: "0.1.0".into(),
        enums: vec![EnumDef {
            name: "Policy".into(),
            rust_path: "test_lib::Policy".into(),
            has_serde: true,
            has_default: true,
            variants: vec![
                EnumVariant {
                    name: "None".into(),
                    ..Default::default()
                },
                EnumVariant {
                    name: "Analyze".into(),
                    fields: vec![FieldDef {
                        name: "label".into(),
                        ty: TypeRef::String,
                        ..Default::default()
                    }],
                    ..Default::default()
                },
            ],
            ..Default::default()
        }],
        types: vec![
            record("Request", "policy", TypeRef::Named("Policy".into())),
            record("Prepared", "request", TypeRef::Named("Request".into())),
            record(
                "Batch",
                "items",
                TypeRef::Vec(Box::new(TypeRef::Named("Prepared".into()))),
            ),
        ],
        ..Default::default()
    }
}

fn fixture_config(binding_directory: &Path) -> ResolvedCrateConfig {
    let config: NewAlefConfig = toml::from_str(
        r#"
[workspace]
languages = ["python"]
[[crates]]
name = "test-lib"
sources = ["src/lib.rs"]
[crates.python]
module_name = "_test_lib"
"#,
    )
    .unwrap();
    let mut config = config.resolve().unwrap().remove(0);
    config
        .output_paths
        .insert("python".into(), binding_directory.join("src"));
    config
}

fn write_fixture(root: &Path) -> std::path::PathBuf {
    let core = root.join("test-lib");
    let binding = root.join("test-lib-py");
    std::fs::create_dir_all(core.join("src")).unwrap();
    std::fs::create_dir_all(binding.join("src")).unwrap();
    std::fs::write(core.join("src/lib.rs"), CORE_SOURCE).unwrap();
    std::fs::write(
        core.join("Cargo.toml"),
        r#"
[package]
name = "test-lib"
version = "0.1.0"
edition = "2024"
[dependencies]
serde = { version = "1", features = ["derive"] }
"#,
    )
    .unwrap();
    std::fs::write(
        binding.join("Cargo.toml"),
        r#"
[package]
name = "test-lib-py"
version = "0.1.0"
edition = "2024"
[dependencies]
pyo3 = "=0.29.2"
serde = { version = "1", features = ["derive"] }
serde_json = "1"
test-lib = { path = "../test-lib" }
"#,
    )
    .unwrap();
    binding
}

#[test]
fn nested_data_enum_dtos_compile_and_round_trip() {
    let temporary_directory = tempfile::tempdir().unwrap();
    let binding = write_fixture(temporary_directory.path());
    let generated = Pyo3Backend
        .generate_bindings(&api_surface(), &fixture_config(&binding))
        .unwrap();
    let mut source = generated[0].content.clone();
    source.push_str(ROUND_TRIP_TEST);
    std::fs::write(binding.join("src/lib.rs"), &source).unwrap();
    let output = std::process::Command::new("cargo")
        .args(["test", "--quiet", "--manifest-path"])
        .arg(binding.join("Cargo.toml"))
        .env("CARGO_TARGET_DIR", temporary_directory.path().join("target"))
        .output()
        .unwrap();
    assert!(
        output.status.success(),
        "generated nested DTO bindings must compile and round-trip:\n{}\n{}\n{source}",
        String::from_utf8_lossy(&output.stdout),
        String::from_utf8_lossy(&output.stderr),
    );
}