canic_testkit/pic/
startup.rs

1use std::{any::Any, panic::catch_unwind};
2
3use pocket_ic::PocketIcBuilder;
4
5use super::Pic;
6
7///
8/// PicStartError
9///
10
11#[derive(Debug, Eq, PartialEq)]
12pub enum PicStartError {
13    BinaryUnavailable { message: String },
14    BinaryInvalid { message: String },
15    DownloadFailed { message: String },
16    ServerStartFailed { message: String },
17    StartupTimedOut { message: String },
18    Panic { message: String },
19}
20
21#[derive(Debug, Eq, PartialEq)]
22pub(super) enum PicPanicKind {
23    DeadInstanceTransport { message: String },
24    Other { message: String },
25}
26
27pub(super) fn try_build_pic(builder: PocketIcBuilder) -> Result<Pic, PicStartError> {
28    let build = catch_unwind(|| builder.build());
29
30    match build {
31        Ok(inner) => Ok(Pic { inner }),
32        Err(payload) => Err(classify_pic_start_panic(payload)),
33    }
34}
35
36impl std::fmt::Display for PicStartError {
37    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
38        match self {
39            Self::BinaryUnavailable { message }
40            | Self::BinaryInvalid { message }
41            | Self::DownloadFailed { message }
42            | Self::ServerStartFailed { message }
43            | Self::StartupTimedOut { message }
44            | Self::Panic { message } => f.write_str(message),
45        }
46    }
47}
48
49impl std::error::Error for PicStartError {}
50
51// Extract a stable string message from one panic payload.
52pub(super) fn panic_payload_to_string(payload: &(dyn Any + Send)) -> String {
53    if let Some(message) = payload.downcast_ref::<String>() {
54        return message.clone();
55    }
56    if let Some(message) = payload.downcast_ref::<&'static str>() {
57        return (*message).to_string();
58    }
59
60    "non-string panic payload".to_string()
61}
62
63// Classify one panic payload so callers can recover dead-instance restores
64// without repeating transport-string matching at each call site.
65pub(super) fn classify_pic_panic(payload: Box<dyn Any + Send>) -> PicPanicKind {
66    let message = panic_payload_to_string(payload.as_ref());
67
68    if is_dead_instance_transport_error(&message) {
69        return PicPanicKind::DeadInstanceTransport { message };
70    }
71
72    PicPanicKind::Other { message }
73}
74
75// Check whether one panic payload belongs to the dead-instance transport class
76// without consuming it, so callers can still resume the original panic.
77pub(super) fn panic_is_dead_instance_transport(payload: &(dyn Any + Send)) -> bool {
78    matches!(
79        classify_pic_panic(Box::new(panic_payload_to_string(payload))),
80        PicPanicKind::DeadInstanceTransport { .. }
81    )
82}
83
84// Detect the PocketIC transport failure class that means the owned instance
85// has already died and cached snapshot restore should rebuild from scratch.
86pub(super) fn is_dead_instance_transport_error(message: &str) -> bool {
87    message.contains("ConnectionRefused")
88        || message.contains("tcp connect error")
89        || message.contains("IncompleteMessage")
90        || message.contains("connection closed before message completed")
91        || message.contains("channel closed")
92}
93
94// Classify one PocketIC startup panic into a typed public error.
95fn classify_pic_start_panic(payload: Box<dyn Any + Send>) -> PicStartError {
96    let message = match classify_pic_panic(payload) {
97        PicPanicKind::DeadInstanceTransport { message } | PicPanicKind::Other { message } => {
98            message
99        }
100    };
101
102    if message.starts_with("Failed to validate PocketIC server binary") {
103        if message.contains("No such file or directory") || message.contains("os error 2") {
104            return PicStartError::BinaryUnavailable { message };
105        }
106
107        return PicStartError::BinaryInvalid { message };
108    }
109
110    if message.starts_with("Failed to download PocketIC server")
111        || message.starts_with("Failed to write PocketIC server binary")
112    {
113        return PicStartError::DownloadFailed { message };
114    }
115
116    if message.starts_with("Failed to start PocketIC binary")
117        || message.starts_with("Failed to create PocketIC server directory")
118    {
119        return PicStartError::ServerStartFailed { message };
120    }
121
122    if message.starts_with("Timed out waiting for PocketIC server being available") {
123        return PicStartError::StartupTimedOut { message };
124    }
125
126    PicStartError::Panic { message }
127}
128
129#[cfg(test)]
130mod tests {
131    use super::{
132        PicPanicKind, PicStartError, classify_pic_panic, classify_pic_start_panic,
133        is_dead_instance_transport_error,
134    };
135
136    #[test]
137    fn pic_start_error_classifies_missing_binary() {
138        let error = classify_pic_start_panic(Box::new(
139            "Failed to validate PocketIC server binary `/tmp/pocket-ic`: `No such file or directory (os error 2)`.".to_string(),
140        ));
141
142        assert!(matches!(error, PicStartError::BinaryUnavailable { .. }));
143    }
144
145    #[test]
146    fn pic_start_error_classifies_failed_spawn() {
147        let error = classify_pic_start_panic(Box::new(
148            "Failed to start PocketIC binary (/tmp/pocket-ic)".to_string(),
149        ));
150
151        assert!(matches!(error, PicStartError::ServerStartFailed { .. }));
152    }
153
154    #[test]
155    fn dead_instance_transport_error_detects_connection_refused() {
156        assert!(is_dead_instance_transport_error(
157            "reqwest::Error { source: ConnectError(\"tcp connect error\", 127.0.0.1:1234, Os { code: 111, kind: ConnectionRefused, message: \"Connection refused\" }) }"
158        ));
159    }
160
161    #[test]
162    fn dead_instance_transport_error_detects_incomplete_message() {
163        assert!(is_dead_instance_transport_error(
164            "reqwest::Error { source: hyper::Error(IncompleteMessage) }"
165        ));
166    }
167
168    #[test]
169    fn classify_pic_panic_marks_dead_instance_transport() {
170        let classified = classify_pic_panic(Box::new(
171            "reqwest::Error { source: hyper::Error(IncompleteMessage) }".to_string(),
172        ));
173
174        assert!(matches!(
175            classified,
176            PicPanicKind::DeadInstanceTransport { .. }
177        ));
178    }
179}
canic_testkit/pic/startup.rs

canic_testkit/pic/
startup.rs
