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| * variable is set to "" | ||
| */ | ||
| std::optional<std::string> getEnvNonEmpty(const std::string & key); | ||
| std::optional<std::string> getEnvNonEmptyOptional(const std::string & key); |
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Renaming this seems unnecessarily churny, plus the "optional" part is already part of the type signature so there's no need to put it in the name.
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The problem is that it looks deceptively simple, and you can't easily tell at a call site. Certainly not when reviewing.
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Is using .value() not enough of an indication?
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Dropped 92767ee for now, so we can already merge the other commits. |
The previous implementation called .value() on std::optional without checking if it had a value. When _NIX_TEST_UNIT_DATA was not set, this would throw std::bad_optional_access or cause a segfault in code that used the raw getenv() result. The new implementation checks the optional first and throws an Error with a helpful message directing users to run tests via meson. The example includes --gdb since this situation may arise when trying to debug tests without knowing about meson's test infrastructure.
The nix_api_store.cc tests and derivation-parser-bench.cc were using raw getenv() calls or unsafe .value() calls on optional, which would segfault when passed to std::filesystem::path constructor if the _NIX_TEST_UNIT_DATA environment variable was not set.
This is mostly theoretical, but the code was calling getenv("TZ")
twice: once to check if it's non-null, and again to get its value.
This creates a potential race condition where the environment could
change between calls.
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Mostly cosmetic, but overall lgtm and improves DX
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