fix(php): support non-nullable unions

.github/workflows/test-pr.yaml

@@ -50,7 +50,7 @@ jobs:
                     # - swift,schema-swift # pgp issue
                     - javascript-prop-types
                     - ruby
-                    - php
+                    - php,schema-php
                     - scala3,schema-scala3
                     - elixir,schema-elixir,graphql-elixir
                     - comment-injection-treesitter,comment-injection-typescript,comment-injection-typescript-zod,comment-injection-typescript-effect-schema

CLAUDE.md

@@ -1,5 +1,32 @@
 # Repository conventions
 
+## Testing
+
+quicktype's primary testing method is end-to-end fixture tests driven by JSON
+and JSON Schema files. For each sample input, the fixture generates code for a
+language, runs a driver program in `test/fixtures/<language>/` that
+deserializes the sample and serializes it back, and compares the round-tripped
+JSON to the input.
+
+- JSON inputs live in `test/inputs/json/`: `priority/` and `samples/` always
+  run, `misc/` is skipped under `QUICKTEST` (and for languages with
+  `skipMiscJSON`).
+- JSON Schema inputs live in `test/inputs/schema/`: each `*.schema` comes with
+  `.N.json` samples and `.N.fail.<feature>.json` expected-failure samples. A
+  fail sample must make the generated program exit nonzero; which fail
+  samples run is controlled by the language's `features` list.
+- Per-language configuration — which inputs run (`skipJSON`, `includeJSON`,
+  `skipSchema`), renderer options, and `features` — lives in
+  `test/languages.ts`; fixtures are registered in `test/fixtures.ts`.
+- Run one language's fixtures with `FIXTURE=<name> script/test`, for example
+  `FIXTURE=php script/test` or `FIXTURE=schema-php script/test`.
+
+Any change that affects generated output MUST be covered by a JSON or JSON
+Schema fixture test — by enabling existing inputs for the language or adding
+new ones. Unit tests in `test/unit/` are a complement for what fixtures cannot
+express (asserting that some code is *not* generated, API-level behavior, fast
+local iteration) — never a substitute.
+
 ## Releasing / version bumps
 
 Do not bump versions in any `package.json` before a release. Package manifest