Convert macro panics to compile errors - #21
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## master #21 +/- ##
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+ Coverage 79.46% 80.74% +1.28%
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Files 9 9
Lines 448 561 +113
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+ Hits 356 453 +97
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The RustEmbed derive macro previously called panic!() and .unwrap() on misconfiguration (non-unit struct, missing/duplicate folder, bad path interpolation, missing CARGO_MANIFEST_DIR, multiple prefixes). These produced opaque macro-expansion panics. Thread syn::Result through impl_rust_embed_for_web and emit syn::Error::new_spanned(...).to_compile_error() so users get proper compile-time diagnostics pointing at the derive instead of a panic. Ports upstream rust-embed commit 7a14d89. Claude-Session: https://claude.ai/code/session_01MixCkrYqoVEZZbPRRNtL3M
Apply rustfmt to the multi-argument generate_*_impl calls so the format check passes, and add unit tests that exercise impl_rust_embed_for_web directly: enum target, struct with fields, missing folder attribute, duplicate folder attributes, duplicate prefix attributes, and a valid unit struct. These cover the new syn::Error compile-error paths that the patch added. Claude-Session: https://claude.ai/code/session_01MixCkrYqoVEZZbPRRNtL3M
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The allow_missing change on master still panicked when the folder is missing and the opt-in is not set. Return a syn::Error like the other misconfiguration paths so it surfaces as a normal compile error. Add tests for both the missing-folder error and the allow_missing opt-in success path. Claude-Session: https://claude.ai/code/session_01MixCkrYqoVEZZbPRRNtL3M
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* Bump version to 11.4.0 Releases changes since 11.3.0: - Add allow_missing derive attribute (#22) - Convert macro panics to compile errors (#21) - Use sorted const table + binary search for embedded get() (#24) - Update sha2 dependency to 0.11 (#25) * Pin time below 0.3.52 in dev-dependencies time 0.3.52 changed the Parsable::parse signature, which breaks cookie 0.16.2 (pulled in transitively via the actix-web dev-dependency), failing the CI doc test job. Constrain to the 0.3 series below 0.3.52 so it unifies with cookie's requirement.
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impl/src/lib.rs uses syn::Error::new_spanned (added in #21), which needs the ToTokens trait from syn's "printing" feature. impl/Cargo.toml sets default-features = false without it, so the crate fails to compile when built in isolation — which is exactly what cargo publish's verification step does. The workspace test build passed only because feature unification pulled "printing" in via another crate. utils 11.4.0 already published before impl failed, so bump all crates to 11.4.1 to re-release cleanly.
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Ports the "Move Panics to Compile Errors" change from upstream rust-embed (commit 7a14d89).
What changed
The
RustEmbedderive macro previously calledpanic!()and.unwrap()when it hit a misconfiguration during macro expansion:folderattributeshellexpandinterpolation (interpolate-folder-pathfeature)CARGO_MANIFEST_DIRprefixattributeThese surfaced as opaque macro-expansion panics. Now
impl_rust_embed_for_webreturnssyn::Result<TokenStream2>and each error path emitssyn::Error::new_spanned(ast, msg). The publicderive(RustEmbed)entry converts a returnedErrintoe.to_compile_error(), so users get a normal compile error pointing at the derive.Valid inputs are unchanged: the generated code is identical, only the error paths differ.
Verification
cargo buildcargo testcargo test --all-featuresAll pass.
https://claude.ai/code/session_01MixCkrYqoVEZZbPRRNtL3M