Codegen / IR tests

Per-crate, snapshot-based. Live under crates/ethercat-esi-codegen/tests/.

Test Case: Name sanitisation handles ESI naming edge cases TEST_0410
status: open
verifies: REQ_0511

Parameterised test asserting the sanitisation map for a fixed table of ESI product names → Rust idents: EL3001-0000 → EL3001_0000, EL3204 with spaces → EL3204_with_spaces, leading-digit 1234-Module → _1234_Module, empty / pure punctuation → error.
Test Case: Revision collision produces distinct idents TEST_0411
status: open
verifies: REQ_0512

Synthetic input set containing two devices with identical product name but different revisions (0x00100000 and 0x00110000). The generated module shall contain EL3204_REV0010 and EL3204_REV0011 (or equivalent deterministic suffixing). Reordering the input file list shall produce the same idents in the same definitions (assert via string comparison of generated source).
Test Case: PDO entry dedup collapses structurally identical layouts TEST_0412
status: open
verifies: REQ_0513

Two synthetic devices whose RxPDO entries have identical (field order, bit lengths, data types) produce a single shared PDO entry struct in the generated module; the two device structs reference it by name. Asserted by counting distinct PdoEntry-bearing struct definitions in the TokenStream (expect 1, not 2).
Test Case: TokenStream emission, not string formatting TEST_0413
status: open
verifies: REQ_0514

White-box test inside ethercat-esi-codegen asserts that emit_device and emit_module_root return TokenStream values directly (compile-time check via the return type). A complementary lint forbids format! / write! / writeln! invocations within the codegen crate’s source.