Closes #14

tests/README.md

@@ -24,7 +24,7 @@ make -j
 make check
 ```
 
-Or run `./tests/dbc_tests` directly. Parser, decoder, and additional coverage
+Or run `./tests/dbc_tests` directly. Parser, decoder, lifetime, and additional coverage
 suites run, and the executable returns nonzero when any suite fails. Decoder cases appear as
 individual QtTest data rows; parser checks are grouped into named test slots.
 Checks also run in release builds.
@@ -41,7 +41,7 @@ make check
 ```
 
 `parser_tests.pri` and `decoder_tests.pri` include the original test sources;
-`tests.pro` also includes `dbc_coverage_test.cpp`.
+`tests.pro` also includes `dbc_coverage_test.cpp` and `dbc_lifetime_test.cpp`.
 `../core/core.pri` supplies the library include path and linkage.
 
 ## Decoder coverage
@@ -120,3 +120,19 @@ API, verify source locations, and check that ambiguous targets receive no values
 All QtTest targets use Qt 6.8.2 and `QVERIFY_THROWS_EXCEPTION`. Exception tests
 explicitly discard `nodiscard` results when only the exception is being checked.
 The standalone tree test requires only a C++17 compiler.
+
+## Definition lifetime and reload coverage
+
+`dbc_lifetime_test.cpp` checks retained definitions and value-description strings
+across reload, clear, and destruction; independently saved signal results;
+copied/moved results and database copies; owning lookup handles; and release of
+the old snapshot after its final owner is removed. Compile-time checks enforce
+const access to runtime metadata. Reload fixtures change ordering, frame names,
+scaling, units, and descriptions, remove definitions, and rename signals.
+
+Key tests check equality and hashing, standard/extended separation, the same
+signal name in different frames, and missing lookups. Constructor tests reject
+duplicate runtime keys, including manually supplied parsed metadata. Failed reload
+leaves the active database intact; empty reload clears it. Invalid/unknown results
+and insufficient payloads retain their documented ownership and status behavior.
+Inactive branches and unavailable selectors also retain definitions across reload.