TestAssertionFailure: retain full error chain in message#666
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rursprung wants to merge 1 commit intogoogle:mainfrom
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TestAssertionFailure: retain full error chain in message#666rursprung wants to merge 1 commit intogoogle:mainfrom
TestAssertionFailure: retain full error chain in message#666rursprung wants to merge 1 commit intogoogle:mainfrom
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so far the conversion from an `Error` to a `TestAssertionFailure` meant that all information about the source errors were lost. often, the `Display` implementation for `Error` implementations does not include the source information since that should instead be retrieved via `source`. while this has not yet been made into an official API guideline (see [rust-lang/api-guidelines#210]) this is nevertheless being followed. various crates like `anyhow` or `eyere` take care of pretty-printing the error chain on failure, however this does not work with `googletest` since `googletest::Result` has `TestAssertionFailure` as the error type which swallows any `Error` and only keeps the message. to resolve this a simple error chain implementation is added to the `From` implementation which pretty-prints the error chain. example: ``` Error: test3 Caused by: 1: test2 2: test1 ``` fixes google#657 [rust-lang/api-guidelines#210]: rust-lang/api-guidelines#210
gribozavr
requested changes
Aug 20, 2025
| let source2 = CustomError { message: "test2".to_string(), source: Some(source1.into()) }; | ||
| let error = CustomError { message: "test3".to_string(), source: Some(source2.into()) }; | ||
| let assertion_failure = TestAssertionFailure::from(error); | ||
| assert_eq!(assertion_failure.description, "Error: test3\n\nCaused by:\n1: test2\n2: test1"); |
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Suggested change
| assert_eq!(assertion_failure.description, "Error: test3\n\nCaused by:\n1: test2\n2: test1"); | |
| verify_eq!(assertion_failure.description, "Error: test3\n\nCaused by:\n1: test2\n2: test1") |
... and change the return type to Result<()> (see comment above)
| use std::fmt::{Debug, Display, Formatter}; | ||
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| #[test] | ||
| fn error_chain_from_error() { |
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| fn error_chain_from_error() { | |
| fn test_assertion_failure_chain_from_error() -> Result<()>{ |
| } | ||
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| #[cfg(test)] | ||
| mod tests { |
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Could you do a bit more testing:
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Check whether we can / should update the error message verification in
test_can_return_anyhow_generated_error()in integration_tests/src/integration_tests.rs -
Add a new integration test that returns a Result with a custom error type like integration_tests/src/test_returning_anyhow_error.rs
Collaborator
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Thank you for the fix! This PR generally looks good, only a few stylistic comments and a request to add an integration test. |
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so far the conversion from an
Errorto aTestAssertionFailuremeant that all information about the source errors were lost. often, theDisplayimplementation forErrorimplementations does not include the source information since that should instead be retrieved viasource. while this has not yet been made into an official API guideline (see rust-lang/api-guidelines#210) this is nevertheless being followed.various crates like
anyhoworeyeretake care of pretty-printing the error chain on failure, however this does not work withgoogletestsincegoogletest::ResulthasTestAssertionFailureas the error type which swallows anyErrorand only keeps the message.to resolve this a simple error chain implementation is added to the
Fromimplementation which pretty-prints the error chain.example:
fixes #657