alef 0.23.39

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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270

use super::*;

#[test]
fn test_gen_ffi_error_codes() {
    let error = sample_error();
    let output = gen_ffi_error_codes(&error);
    assert!(output.contains("CONVERSION_ERROR_NONE = 0"));
    assert!(output.contains("CONVERSION_ERROR_PARSE_ERROR = 1"));
    assert!(output.contains("CONVERSION_ERROR_IO_ERROR = 2"));
    assert!(output.contains("CONVERSION_ERROR_OTHER = 3"));
    assert!(output.contains("conversion_error_t;"));
    assert!(output.contains("conversion_error_error_message(conversion_error_t code)"));
}

// -----------------------------------------------------------------------
// Go tests
// -----------------------------------------------------------------------

#[test]
fn test_gen_go_error_types() {
    let error = sample_error();
    // Package name that does NOT match the error prefix — type name stays unchanged.
    let output = gen_go_error_types(&error, "mylib");
    assert!(output.contains("ErrParseError = errors.New("));
    assert!(output.contains("ErrIoError = errors.New("));
    assert!(output.contains("ErrOther = errors.New("));
    assert!(output.contains("type ConversionError struct {"));
    assert!(output.contains("Code    string"));
    assert!(output.contains("func (e ConversionError) Error() string"));
    // Each sentinel error var should have a doc comment.
    assert!(output.contains("// ErrParseError is returned when"));
    assert!(output.contains("// ErrIoError is returned when"));
    assert!(output.contains("// ErrOther is returned when"));
}

#[test]
fn test_gen_go_error_types_stutter_strip() {
    let error = sample_error();
    // "conversion" package — "ConversionError" starts with "conversion" (case-insensitive)
    // so the exported Go type should be "Error", not "ConversionError".
    let output = gen_go_error_types(&error, "conversion");
    assert!(
        output.contains("type Error struct {"),
        "expected stutter strip, got:\n{output}"
    );
    assert!(
        output.contains("func (e Error) Error() string"),
        "expected stutter strip, got:\n{output}"
    );
    // Sentinel vars are unaffected by stutter stripping.
    assert!(output.contains("ErrParseError = errors.New("));
}

// -----------------------------------------------------------------------
// Java tests
// -----------------------------------------------------------------------

#[test]
fn test_gen_java_error_types() {
    let error = sample_error();
    let files = gen_java_error_types(&error, "dev.sample_crate.test");
    // base + 3 variants
    assert_eq!(files.len(), 4);
    // Base class
    assert_eq!(files[0].0, "ConversionErrorException");
    assert!(
        files[0]
            .1
            .contains("public class ConversionErrorException extends Exception")
    );
    assert!(files[0].1.contains("package dev.sample_crate.test;"));
    // Variant classes
    assert_eq!(files[1].0, "ParseErrorException");
    assert!(
        files[1]
            .1
            .contains("public class ParseErrorException extends ConversionErrorException")
    );
    assert_eq!(files[2].0, "IoErrorException");
    assert_eq!(files[3].0, "OtherException");
}

// -----------------------------------------------------------------------
// C# tests
// -----------------------------------------------------------------------

#[test]
fn test_gen_csharp_error_types() {
    let error = sample_error();
    // Without fallback class: base inherits from Exception.
    let files = gen_csharp_error_types(&error, "SampleCrate.Test", None);
    assert_eq!(files.len(), 4);
    assert_eq!(files[0].0, "ConversionErrorException");
    assert!(files[0].1.contains("public class ConversionErrorException : Exception"));
    assert!(files[0].1.contains("namespace SampleCrate.Test;"));
    assert_eq!(files[1].0, "ParseErrorException");
    assert!(
        files[1]
            .1
            .contains("public class ParseErrorException : ConversionErrorException")
    );
    assert_eq!(files[2].0, "IoErrorException");
    assert_eq!(files[3].0, "OtherException");
}

#[test]
fn test_gen_csharp_error_types_with_fallback() {
    let error = sample_error();
    // With fallback class: base inherits from the generic library exception.
    let files = gen_csharp_error_types(&error, "SampleCrate.Test", Some("TestLibException"));
    assert_eq!(files.len(), 4);
    assert!(
        files[0]
            .1
            .contains("public class ConversionErrorException : TestLibException")
    );
    // Variant classes still inherit from the base error class, not from the fallback directly.
    assert!(
        files[1]
            .1
            .contains("public class ParseErrorException : ConversionErrorException")
    );
}

// -----------------------------------------------------------------------
// python_exception_name tests
// -----------------------------------------------------------------------

#[test]
fn test_python_exception_name_no_conflict() {
    // "ParseError" already ends with "Error" and is not a builtin
    assert_eq!(python_exception_name("ParseError", "ConversionError"), "ParseError");
    // "Other" gets "Error" suffix, "OtherError" is not a builtin
    assert_eq!(python_exception_name("Other", "ConversionError"), "OtherError");
}

#[test]
fn test_python_exception_name_shadows_builtin() {
    // "Connection" -> "ConnectionError" shadows builtin -> prefix with "Crawl"
    assert_eq!(
        python_exception_name("Connection", "CrawlError"),
        "CrawlConnectionError"
    );
    // "Timeout" -> "TimeoutError" shadows builtin -> prefix with "Crawl"
    assert_eq!(python_exception_name("Timeout", "CrawlError"), "CrawlTimeoutError");
    // "ConnectionError" already ends with "Error", still shadows -> prefix
    assert_eq!(
        python_exception_name("ConnectionError", "CrawlError"),
        "CrawlConnectionError"
    );
}

#[test]
fn test_python_exception_name_no_double_prefix() {
    // If variant is already prefixed with the error base, don't double-prefix
    assert_eq!(
        python_exception_name("CrawlConnectionError", "CrawlError"),
        "CrawlConnectionError"
    );
}

// -----------------------------------------------------------------------
// WASM error methods tests
// -----------------------------------------------------------------------

#[test]
fn test_gen_wasm_error_methods_empty_when_no_methods() {
    let error = sample_error(); // methods: vec![]
    let output = gen_wasm_error_methods(&error, "sample_markup_rs", "");
    assert!(output.is_empty(), "should produce no output when methods is empty");
}

#[test]
fn test_gen_wasm_error_methods_struct_and_impl() {
    let error = error_with_methods();
    // wasm_prefix is the full type prefix, e.g. "Wasm" — the struct name is
    // {wasm_prefix}{ErrorName} = "WasmSampleAppError".
    let output = gen_wasm_error_methods(&error, "sample_app", "Wasm");
    // Struct definition
    assert!(
        output.contains("pub struct WasmSampleAppError"),
        "must emit opaque struct: {output}"
    );
    assert!(
        output.contains("pub(crate) inner: sample_app::error::SampleAppError"),
        "{output}"
    );
    // Impl block
    assert!(output.contains("#[wasm_bindgen]\nimpl WasmSampleAppError"), "{output}");
    // Methods with camelCase js_name
    assert!(output.contains("js_name = \"statusCode\""), "{output}");
    assert!(output.contains("pub fn status_code(&self) -> u16"), "{output}");
    assert!(output.contains("self.inner.status_code()"), "{output}");
    assert!(output.contains("js_name = \"isTransient\""), "{output}");
    assert!(output.contains("pub fn is_transient(&self) -> bool"), "{output}");
    assert!(output.contains("self.inner.is_transient()"), "{output}");
    assert!(output.contains("js_name = \"errorType\""), "{output}");
    assert!(output.contains("pub fn error_type(&self) -> String"), "{output}");
    assert!(output.contains("self.inner.error_type().to_string()"), "{output}");
}

// -----------------------------------------------------------------------
// FFI error methods tests
// -----------------------------------------------------------------------

#[test]
fn test_gen_ffi_error_methods_empty_when_no_methods() {
    let error = sample_error(); // methods: vec![]
    let output = gen_ffi_error_methods(&error, "sample_markup_rs", "sample_markup");
    assert!(output.is_empty(), "should produce no output when methods is empty");
}

#[test]
fn test_gen_ffi_error_methods_status_code() {
    let error = error_with_methods();
    let output = gen_ffi_error_methods(&error, "sample_app", "sampleapp");
    assert!(
        output.contains("pub unsafe extern \"C\" fn sampleapp_sample_app_error_status_code("),
        "must emit status_code fn: {output}"
    );
    assert!(
        output.contains("err: *const sample_app::error::SampleAppError"),
        "{output}"
    );
    assert!(output.contains("-> u16"), "{output}");
    assert!(output.contains("(*err).status_code()"), "{output}");
    assert!(output.contains("if err.is_null()"), "{output}");
    assert!(output.contains("return 0;"), "{output}");
}

#[test]
fn test_gen_ffi_error_methods_is_transient() {
    let error = error_with_methods();
    let output = gen_ffi_error_methods(&error, "sample_app", "sampleapp");
    assert!(
        output.contains("pub unsafe extern \"C\" fn sampleapp_sample_app_error_is_transient("),
        "must emit is_transient fn: {output}"
    );
    assert!(output.contains("-> bool"), "{output}");
    assert!(output.contains("(*err).is_transient()"), "{output}");
    assert!(output.contains("return false;"), "{output}");
}

#[test]
fn test_gen_ffi_error_methods_error_type_with_free() {
    let error = error_with_methods();
    let output = gen_ffi_error_methods(&error, "sample_app", "sampleapp");
    assert!(
        output.contains("pub unsafe extern \"C\" fn sampleapp_sample_app_error_error_type("),
        "must emit error_type fn: {output}"
    );
    assert!(output.contains("-> *mut std::ffi::c_char"), "{output}");
    assert!(output.contains("(*err).error_type()"), "{output}");
    assert!(output.contains("CString::new(s)"), "{output}");
    assert!(output.contains(".into_raw()"), "{output}");
    assert!(output.contains("return std::ptr::null_mut();"), "{output}");
    // free companion
    assert!(
        output.contains("pub unsafe extern \"C\" fn sampleapp_sample_app_error_error_type_free("),
        "must emit _free companion: {output}"
    );
    assert!(output.contains("drop(std::ffi::CString::from_raw(ptr))"), "{output}");
}

#[test]
fn test_gen_ffi_error_methods_safety_comments() {
    let error = error_with_methods();
    let output = gen_ffi_error_methods(&error, "sample_app", "sampleapp");
    assert!(output.contains("// SAFETY:"), "must include SAFETY comments: {output}");
}