39 lines
1.2 KiB
Plaintext
39 lines
1.2 KiB
Plaintext
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== Why is this an issue?
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Using `unwrap()` in conditions where it will always fail leads to unexpected panics and unclear error handling. It's likely a mistake and checking that there is indeed a wrapped value and not a none one was intended instead, which would require inverting the condition. However, if panicking was indeed intended, then one should use `panic!` explicitly to make the intention clear and readable.
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=== Code examples
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==== Noncompliant code example
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[source,rust,diff-id=1,diff-type=noncompliant]
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----
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let option = Some(0);
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fn do_something_with(_x: usize) {}
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if option.is_none() {
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do_something_with(option.unwrap()); // Noncompliant: This code will always panic.
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}
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----
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==== Compliant solution
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[source,rust,diff-id=1,diff-type=compliant]
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----
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let option = Some(0);
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fn do_something_with(_x: usize) {}
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if option.is_some() {
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do_something_with(option.unwrap()); // Compliant: Inverted condition to ensure unwrap is safe.
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}
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// or
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if option.is_none() {
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panic!("Option was none when it was expected to be some."); // Compliant: Explicit panic with a message.
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}
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----
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== Resources
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=== Documentation
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* Clippy Lints - https://rust-lang.github.io/rust-clippy/master/index.html#panicking_unwrap
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