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
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
//-
// Copyright 2017, 2018, 2019 The proptest developers
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use crate::std_facade::Box;
use core::u32;

#[cfg(feature = "std")]
use std::env;
#[cfg(feature = "std")]
use std::ffi::OsString;
#[cfg(feature = "std")]
use std::fmt;
#[cfg(feature = "std")]
use std::str::FromStr;

use crate::test_runner::result_cache::{noop_result_cache, ResultCache};
use crate::test_runner::rng::RngAlgorithm;
use crate::test_runner::FailurePersistence;
#[cfg(feature = "std")]
use crate::test_runner::FileFailurePersistence;

#[cfg(feature = "std")]
const CASES: &str = "PROPTEST_CASES";
#[cfg(feature = "std")]
const MAX_LOCAL_REJECTS: &str = "PROPTEST_MAX_LOCAL_REJECTS";
#[cfg(feature = "std")]
const MAX_GLOBAL_REJECTS: &str = "PROPTEST_MAX_GLOBAL_REJECTS";
#[cfg(feature = "std")]
const MAX_FLAT_MAP_REGENS: &str = "PROPTEST_MAX_FLAT_MAP_REGENS";
#[cfg(feature = "std")]
const MAX_SHRINK_TIME: &str = "PROPTEST_MAX_SHRINK_TIME";
#[cfg(feature = "std")]
const MAX_SHRINK_ITERS: &str = "PROPTEST_MAX_SHRINK_ITERS";
#[cfg(feature = "fork")]
const FORK: &str = "PROPTEST_FORK";
#[cfg(feature = "timeout")]
const TIMEOUT: &str = "PROPTEST_TIMEOUT";
#[cfg(feature = "std")]
const VERBOSE: &str = "PROPTEST_VERBOSE";
const RNG_ALGORITHM: &str = "PROPTEST_RNG_ALGORITHM";

#[cfg(feature = "std")]
fn contextualize_config(mut result: Config) -> Config {
    fn parse_or_warn<T: FromStr + fmt::Display>(
        src: &OsString,
        dst: &mut T,
        typ: &str,
        var: &str,
    ) {
        if let Some(src) = src.to_str() {
            if let Ok(value) = src.parse() {
                *dst = value;
            } else {
                eprintln!(
                    "proptest: The env-var {}={} can't be parsed as {}, \
                     using default of {}.",
                    var, src, typ, *dst
                );
            }
        } else {
            eprintln!(
                "proptest: The env-var {} is not valid, using \
                 default of {}.",
                var, *dst
            );
        }
    }

    result.failure_persistence =
        Some(Box::new(FileFailurePersistence::default()));
    for (var, value) in
        env::vars_os().filter_map(|(k, v)| k.into_string().ok().map(|k| (k, v)))
    {
        match var.as_str() {
            CASES => parse_or_warn(&value, &mut result.cases, "u32", CASES),
            MAX_LOCAL_REJECTS => parse_or_warn(
                &value,
                &mut result.max_local_rejects,
                "u32",
                MAX_LOCAL_REJECTS,
            ),
            MAX_GLOBAL_REJECTS => parse_or_warn(
                &value,
                &mut result.max_global_rejects,
                "u32",
                MAX_GLOBAL_REJECTS,
            ),
            MAX_FLAT_MAP_REGENS => parse_or_warn(
                &value,
                &mut result.max_flat_map_regens,
                "u32",
                MAX_FLAT_MAP_REGENS,
            ),
            #[cfg(feature = "fork")]
            FORK => parse_or_warn(&value, &mut result.fork, "bool", FORK),
            #[cfg(feature = "timeout")]
            TIMEOUT => {
                parse_or_warn(&value, &mut result.timeout, "timeout", TIMEOUT)
            }
            MAX_SHRINK_TIME => parse_or_warn(
                &value,
                &mut result.max_shrink_time,
                "u32",
                MAX_SHRINK_TIME,
            ),
            MAX_SHRINK_ITERS => parse_or_warn(
                &value,
                &mut result.max_shrink_iters,
                "u32",
                MAX_SHRINK_ITERS,
            ),
            VERBOSE => {
                parse_or_warn(&value, &mut result.verbose, "u32", VERBOSE)
            }
            RNG_ALGORITHM => parse_or_warn(
                &value,
                &mut result.rng_algorithm,
                "RngAlgorithm",
                RNG_ALGORITHM,
            ),

            _ => {
                if var.starts_with("PROPTEST_") {
                    eprintln!("proptest: Ignoring unknown env-var {}.", var);
                }
            }
        }
    }

    result
}

#[cfg(not(feature = "std"))]
fn contextualize_config(result: Config) -> Config {
    result
}

fn default_default_config() -> Config {
    Config {
        cases: 256,
        max_local_rejects: 65_536,
        max_global_rejects: 1024,
        max_flat_map_regens: 1_000_000,
        failure_persistence: None,
        source_file: None,
        test_name: None,
        #[cfg(feature = "fork")]
        fork: false,
        #[cfg(feature = "timeout")]
        timeout: 0,
        #[cfg(feature = "std")]
        max_shrink_time: 0,
        max_shrink_iters: u32::MAX,
        result_cache: noop_result_cache,
        #[cfg(feature = "std")]
        verbose: 0,
        rng_algorithm: RngAlgorithm::default(),
        _non_exhaustive: (),
    }
}

// The default config, computed by combining environment variables and
// defaults.
#[cfg(feature = "std")]
lazy_static! {
    static ref DEFAULT_CONFIG: Config =
        contextualize_config(default_default_config());
}

/// Configuration for how a proptest test should be run.
#[derive(Clone, Debug, PartialEq)]
pub struct Config {
    /// The number of successful test cases that must execute for the test as a
    /// whole to pass.
    ///
    /// This does not include implicitly-replayed persisted failing cases.
    ///
    /// The default is 256, which can be overridden by setting the
    /// `PROPTEST_CASES` environment variable.
    pub cases: u32,

    /// The maximum number of individual inputs that may be rejected before the
    /// test as a whole aborts.
    ///
    /// The default is 65536, which can be overridden by setting the
    /// `PROPTEST_MAX_LOCAL_REJECTS` environment variable.
    pub max_local_rejects: u32,

    /// The maximum number of combined inputs that may be rejected before the
    /// test as a whole aborts.
    ///
    /// The default is 1024, which can be overridden by setting the
    /// `PROPTEST_MAX_GLOBAL_REJECTS` environment variable.
    pub max_global_rejects: u32,

    /// The maximum number of times all `Flatten` combinators will attempt to
    /// regenerate values. This puts a limit on the worst-case exponential
    /// explosion that can happen with nested `Flatten`s.
    ///
    /// The default is 1_000_000, which can be overridden by setting the
    /// `PROPTEST_MAX_FLAT_MAP_REGENS` environment variable.
    pub max_flat_map_regens: u32,

    /// Indicates whether and how to persist failed test results.
    ///
    /// When compiling with "std" feature (i.e. the standard library is available), the default
    /// is `Some(Box::new(FileFailurePersistence::SourceParallel("proptest-regressions")))`.
    ///
    /// Without the standard library, the default is `None`, and no persistence occurs.
    ///
    /// See the docs of [`FileFailurePersistence`](enum.FileFailurePersistence.html)
    /// and [`MapFailurePersistence`](struct.MapFailurePersistence.html) for more information.
    ///
    /// The default cannot currently be overridden by an environment variable.
    pub failure_persistence: Option<Box<dyn FailurePersistence>>,

    /// File location of the current test, relevant for persistence
    /// and debugging.
    ///
    /// Note the use of `&str` rather than `Path` to be compatible with
    /// `#![no_std]` use cases where `Path` is unavailable.
    ///
    /// See the docs of [`FileFailurePersistence`](enum.FileFailurePersistence.html)
    /// for more information on how it may be used for persistence.
    pub source_file: Option<&'static str>,

    /// The fully-qualified name of the test being run, as would be passed to
    /// the test executable to run just that test.
    ///
    /// This must be set if `fork` is `true`. Otherwise, it is unused. It is
    /// automatically set by `proptest!`.
    ///
    /// This must include the crate name at the beginning, as produced by
    /// `module_path!()`.
    pub test_name: Option<&'static str>,

    /// If true, tests are run in a subprocess.
    ///
    /// Forking allows proptest to work with tests which may fail by aborting
    /// the process, causing a segmentation fault, etc, but can be a lot slower
    /// in certain environments or when running a very large number of tests.
    ///
    /// For forking to work correctly, both the `Strategy` and the content of
    /// the test case itself must be deterministic.
    ///
    /// This requires the "fork" feature, enabled by default.
    ///
    /// The default is `false`, which can be overridden by setting the
    /// `PROPTEST_FORK` environment variable.
    #[cfg(feature = "fork")]
    pub fork: bool,

    /// If non-zero, tests are run in a subprocess and each generated case
    /// fails if it takes longer than this number of milliseconds.
    ///
    /// This implicitly enables forking, even if the `fork` field is `false`.
    ///
    /// The type here is plain `u32` (rather than
    /// `Option<std::time::Duration>`) for the sake of ergonomics.
    ///
    /// This requires the "timeout" feature, enabled by default.
    ///
    /// Setting a timeout to less than the time it takes the process to start
    /// up and initialise the first test case will cause the whole test to be
    /// aborted.
    ///
    /// The default is `0` (i.e., no timeout), which can be overridden by
    /// setting the `PROPTEST_TIMEOUT` environment variable.
    #[cfg(feature = "timeout")]
    pub timeout: u32,

    /// If non-zero, give up the shrinking process after this many milliseconds
    /// have elapsed since the start of the shrinking process.
    ///
    /// This will not cause currently running test cases to be interrupted.
    ///
    /// This configuration is only available when the `std` feature is enabled
    /// (which it is by default).
    ///
    /// The default is `0` (i.e., no limit), which can be overridden by setting
    /// the `PROPTEST_MAX_SHRINK_TIME` environment variable.
    #[cfg(feature = "std")]
    pub max_shrink_time: u32,

    /// Give up on shrinking if more than this number of iterations of the test
    /// code are run.
    ///
    /// Setting this to `std::u32::MAX` causes the actual limit to be four
    /// times the number of test cases.
    ///
    /// Setting this value to `0` disables shrinking altogether.
    ///
    /// Note that the type of this field will change in a future version of
    /// proptest to better accommodate its special values.
    ///
    /// The default is `std::u32::MAX`, which can be overridden by setting the
    /// `PROPTEST_MAX_SHRINK_ITERS` environment variable.
    pub max_shrink_iters: u32,

    /// A function to create new result caches.
    ///
    /// The default is to do no caching. The easiest way to enable caching is
    /// to set this field to `basic_result_cache` (though that is currently
    /// only available with the `std` feature).
    ///
    /// This is useful for strategies which have a tendency to produce
    /// duplicate values, or for tests where shrinking can take a very long
    /// time due to exploring the same output multiple times.
    ///
    /// When caching is enabled, generated values themselves are not stored, so
    /// this does not pose a risk of memory exhaustion for large test inputs
    /// unless using extraordinarily large test case counts.
    ///
    /// Caching incurs its own overhead, and may very well make your test run
    /// more slowly.
    pub result_cache: fn() -> Box<dyn ResultCache>,

    /// Set to non-zero values to cause proptest to emit human-targeted
    /// messages to stderr as it runs.
    ///
    /// Greater values cause greater amounts of logs to be emitted. The exact
    /// meaning of certain levels other than 0 is subject to change.
    ///
    /// - 0: No extra output.
    /// - 1: Log test failure messages.
    /// - 2: Trace low-level details.
    ///
    /// This is only available with the `std` feature (enabled by default)
    /// since on nostd proptest has no way to produce output.
    ///
    /// The default is `0`, which can be overridden by setting the
    /// `PROPTEST_VERBOSE` environment variable.
    #[cfg(feature = "std")]
    pub verbose: u32,

    /// The RNG algorithm to use when not using a user-provided RNG.
    ///
    /// The default is `RngAlgorithm::default()`, which can be overridden by
    /// setting the `PROPTEST_RNG_ALGORITHM` environment variable to one of the following:
    ///
    /// - `xs` — `RngAlgorithm::XorShift`
    /// - `cc` — `RngAlgorithm::ChaCha`
    pub rng_algorithm: RngAlgorithm,

    // Needs to be public so FRU syntax can be used.
    #[doc(hidden)]
    pub _non_exhaustive: (),
}

impl Config {
    /// Constructs a `Config` only differing from the `default()` in the
    /// number of test cases required to pass the test successfully.
    ///
    /// This is simply a more concise alternative to using field-record update
    /// syntax:
    ///
    /// ```
    /// # use proptest::test_runner::Config;
    /// assert_eq!(
    ///     Config::with_cases(42),
    ///     Config { cases: 42, .. Config::default() }
    /// );
    /// ```
    pub fn with_cases(cases: u32) -> Self {
        Self {
            cases,
            ..Config::default()
        }
    }

    /// Constructs a `Config` only differing from the `default()` in the
    /// source_file of the present test.
    ///
    /// This is simply a more concise alternative to using field-record update
    /// syntax:
    ///
    /// ```
    /// # use proptest::test_runner::Config;
    /// assert_eq!(
    ///     Config::with_source_file("computer/question"),
    ///     Config { source_file: Some("computer/question"), .. Config::default() }
    /// );
    /// ```
    pub fn with_source_file(source_file: &'static str) -> Self {
        Self {
            source_file: Some(source_file),
            ..Config::default()
        }
    }

    /// Constructs a `Config` only differing from the provided Config instance, `self`,
    /// in the source_file of the present test.
    ///
    /// This is simply a more concise alternative to using field-record update
    /// syntax:
    ///
    /// ```
    /// # use proptest::test_runner::Config;
    /// let a = Config::with_source_file("computer/question");
    /// let b = a.clone_with_source_file("answer/42");
    /// assert_eq!(
    ///     a,
    ///     Config { source_file: Some("computer/question"), .. Config::default() }
    /// );
    /// assert_eq!(
    ///     b,
    ///     Config { source_file: Some("answer/42"), .. Config::default() }
    /// );
    /// ```
    pub fn clone_with_source_file(&self, source_file: &'static str) -> Self {
        let mut result = self.clone();
        result.source_file = Some(source_file);
        result
    }

    /// Return whether this configuration implies forking.
    ///
    /// This method exists even if the "fork" feature is disabled, in which
    /// case it simply returns false.
    pub fn fork(&self) -> bool {
        self._fork() || self.timeout() > 0
    }

    #[cfg(feature = "fork")]
    fn _fork(&self) -> bool {
        self.fork
    }

    #[cfg(not(feature = "fork"))]
    fn _fork(&self) -> bool {
        false
    }

    /// Returns the configured timeout.
    ///
    /// This method exists even if the "timeout" feature is disabled, in which
    /// case it simply returns 0.
    #[cfg(feature = "timeout")]
    pub fn timeout(&self) -> u32 {
        self.timeout
    }

    /// Returns the configured timeout.
    ///
    /// This method exists even if the "timeout" feature is disabled, in which
    /// case it simply returns 0.
    #[cfg(not(feature = "timeout"))]
    pub fn timeout(&self) -> u32 {
        0
    }

    /// Returns the configured limit on shrinking iterations.
    ///
    /// This takes into account the special "automatic" behaviour.
    pub fn max_shrink_iters(&self) -> u32 {
        if u32::MAX == self.max_shrink_iters {
            self.cases.saturating_mul(4)
        } else {
            self.max_shrink_iters
        }
    }

    // Used by macros to force the config to be owned without depending on
    // certain traits being `use`d.
    #[allow(missing_docs)]
    #[doc(hidden)]
    pub fn __sugar_to_owned(&self) -> Self {
        self.clone()
    }
}

#[cfg(feature = "std")]
impl Default for Config {
    fn default() -> Self {
        DEFAULT_CONFIG.clone()
    }
}

#[cfg(not(feature = "std"))]
impl Default for Config {
    fn default() -> Self {
        default_default_config()
    }
}