ic_testkit/pic/
standalone_recipe.rs

1use std::io;
2
3use candid::Principal;
4
5use super::{
6    CachedPocketIcBaseline, CanisterSnapshotTarget, FailureDisposition, PocketIcBaselineRecipe,
7    PreparedBaseline, RebuildReason, ResetReceipt, ResetRequirements, SnapshotRestoreFunding,
8    StandaloneCanisterFixture, is_dead_pocket_ic_transport_error,
9};
10
11/// Snapshot-only recipe for one caller-built, installed canister.
12///
13/// Use with [`super::CachedPocketIcBaselinePool`]. The baseline metadata is the
14/// installed canister ID; calls go through the baseline's borrowed PocketIC.
15/// The builder owns initialization and readiness before capture and must produce
16/// the same topology and seeded state for every slot of this recipe. It returns
17/// `io::Result<StandaloneCanisterFixture>`; build errors retain their original
18/// cause and are reported at the pool's build stage, without invoking capture.
19///
20/// Only the captured canister is restored. Time, other canisters, pending work
21/// and external resources are not reset. Use a custom recipe or a fresh instance
22/// when those mutations matter. Funding is applied immediately before restore.
23/// Non-transport restore failures are fatal: the pool discards the affected
24/// baseline before returning the error. Dead transport permits one recovery build.
25pub struct StandaloneCanisterRecipe<B> {
26    requirements: ResetRequirements,
27    build: B,
28}
29
30impl<B> StandaloneCanisterRecipe<B> {
31    /// Describe a single-canister recipe without invoking its builder.
32    ///
33    /// Static suites can initialize the recipe and pool with [`std::sync::LazyLock`].
34    #[must_use]
35    pub fn new(funding: SnapshotRestoreFunding, build: B) -> Self {
36        Self {
37            requirements: ResetRequirements::try_new(funding, [])
38                .expect("empty non-snapshot requirements are valid"),
39            build,
40        }
41    }
42}
43
44impl<B> PocketIcBaselineRecipe for StandaloneCanisterRecipe<B>
45where
46    B: Fn() -> io::Result<StandaloneCanisterFixture> + Send + Sync + 'static,
47{
48    type Metadata = Principal;
49    // Retain the typed snapshot/contract cause without another error vocabulary.
50    type Error = io::Error;
51
52    fn reset_requirements(&self) -> &ResetRequirements {
53        &self.requirements
54    }
55
56    fn build(&self) -> Result<CachedPocketIcBaseline<Principal>, io::Error> {
57        let (pocket_ic, canister_id) = (self.build)()?.into_parts();
58        CachedPocketIcBaseline::capture(
59            pocket_ic,
60            [CanisterSnapshotTarget {
61                canister_id,
62                sender: None,
63            }],
64            canister_id,
65        )
66        .map_err(io::Error::other)
67    }
68
69    fn reset_non_snapshot_state(
70        &self,
71        _baseline: &CachedPocketIcBaseline<Principal>,
72    ) -> Result<ResetReceipt, io::Error> {
73        Ok(ResetReceipt::empty())
74    }
75
76    fn drive_to_readiness(
77        &self,
78        _baseline: &CachedPocketIcBaseline<Principal>,
79    ) -> Result<(), io::Error> {
80        Ok(())
81    }
82
83    fn validate(
84        &self,
85        _baseline: &CachedPocketIcBaseline<Principal>,
86        _preparation: &PreparedBaseline,
87    ) -> Result<(), io::Error> {
88        Ok(())
89    }
90
91    fn classify_failure(
92        &self,
93        _stage: super::BaselinePreparationStage,
94        error: &(dyn std::error::Error + 'static),
95    ) -> FailureDisposition {
96        if is_dead_pocket_ic_transport_error(error) {
97            FailureDisposition::Rebuild(RebuildReason::DeadPocketIcTransport)
98        } else {
99            FailureDisposition::Fatal
100        }
101    }
102}
103
104#[cfg(test)]
105mod tests {
106    use std::num::NonZeroUsize;
107
108    use super::*;
109    use crate::pic::CachedPocketIcBaselinePool;
110
111    fn build_fixture() -> io::Result<StandaloneCanisterFixture> {
112        panic!("constructing an empty pool must not invoke its builder")
113    }
114
115    #[test]
116    fn runtime_capacity_preserves_lazy_fixture_construction() {
117        for capacity in [1, 2, 4, 8].map(|value| NonZeroUsize::new(value).unwrap()) {
118            let recipe = StandaloneCanisterRecipe::new(
119                SnapshotRestoreFunding::TopUpTo { minimum_cycles: 1 },
120                build_fixture,
121            );
122            let pool = CachedPocketIcBaselinePool::new(capacity, recipe);
123            assert_eq!(pool.capacity(), capacity);
124        }
125    }
126
127    #[test]
128    fn builder_errors_preserve_the_cause_and_release_the_slot_for_another_attempt() {
129        let recipe = StandaloneCanisterRecipe::new(SnapshotRestoreFunding::Preserve, || {
130            Err(io::Error::new(
131                io::ErrorKind::PermissionDenied,
132                std::fmt::Error,
133            ))
134        });
135        let pool = CachedPocketIcBaselinePool::new(NonZeroUsize::new(1).unwrap(), recipe);
136        for _ in 0..2 {
137            let Err(super::super::BaselinePoolError::Preparation {
138                error:
139                    super::super::BaselinePoolPreparationError::Recipe {
140                        stage: super::super::BaselinePreparationStage::Build,
141                        source,
142                    },
143                timings,
144            }) = pool.acquire()
145            else {
146                panic!("builder failure must return at the build stage");
147            };
148            assert_eq!(source.kind(), io::ErrorKind::PermissionDenied);
149            assert!(source.get_ref().unwrap().is::<std::fmt::Error>());
150            assert!(timings.build().is_some());
151            assert!(timings.restore().is_none());
152            assert!(timings.total() >= timings.build().unwrap());
153        }
154    }
155}
ic_testkit/pic/standalone_recipe.rs

ic_testkit/pic/
standalone_recipe.rs
