Keep every README link working on the package page

README.md

@@ -15,9 +15,9 @@ The repo also ships a self-contained **reference bridge demo** (`mqtt_demo/`) th
 
 ## Documentation
 
-- **[`docs/api.md`](docs/api.md)** — the supported API: every name downstream code may import, with its signature. Generated from the code, so it cannot drift.
-- [`docs/ocf-pki-laundry.md`](docs/ocf-pki-laundry.md) — the newer OCF-PKI appliance generation, and why an AC14K_M certificate is refused there.
-- [`docs/ocf-vd-devices.md`](docs/ocf-vd-devices.md) — server-authenticated findings from Samsung VD hardware.
+- **[`docs/api.md`](https://github.com/QuiteYellow/SmartThings-Local/blob/main/docs/api.md)** — the supported API: every name downstream code may import, with its signature. Generated from the code, so it cannot drift.
+- [`docs/ocf-pki-laundry.md`](https://github.com/QuiteYellow/SmartThings-Local/blob/main/docs/ocf-pki-laundry.md) — the newer OCF-PKI appliance generation, and why an AC14K_M certificate is refused there.
+- [`docs/ocf-vd-devices.md`](https://github.com/QuiteYellow/SmartThings-Local/blob/main/docs/ocf-vd-devices.md) — server-authenticated findings from Samsung VD hardware.
 
 ## Quick start (library)
 
@@ -217,7 +217,7 @@ The public API is organized by responsibility rather than re-exported through
 one large root namespace. Explicit imports from these modules are intentional
 and covered by the downstream compatibility contract.
 
-**[`docs/api.md`](docs/api.md) is the full reference**: every supported name, with its signature read off the code. It is generated from `tools/api_contract.py` by `tools/generate_api_docs.py`, and the test suite fails if the page and the code disagree. A public name absent from it is reachable but incidental, and may move. The table below is the map; that page is the inventory.
+**[`docs/api.md`](https://github.com/QuiteYellow/SmartThings-Local/blob/main/docs/api.md) is the full reference**: every supported name, with its signature read off the code. It is generated from `tools/api_contract.py` by `tools/generate_api_docs.py`, and the test suite fails if the page and the code disagree. A public name absent from it is reachable but incidental, and may move. The table below is the map; that page is the inventory.
 
 | Module | Supported responsibility |
 | --- | --- |
@@ -1185,4 +1185,4 @@ This is an independent, unofficial project. It is **not affiliated with, authori
 
 "Samsung", "SmartThings", and any related names, marks, and logos are trademarks of Samsung Electronics Co., Ltd. They are used in this project **only nominatively** — to identify the hardware and protocols this software interoperates with — and no claim is made to any right in them. Use of these marks does not imply any affiliation with or endorsement by their owner.
 
-The software is provided under the [MIT License](LICENSE) for interoperability with hardware you own, without warranty of any kind.
+The software is provided under the [MIT License](https://github.com/QuiteYellow/SmartThings-Local/blob/main/LICENSE) for interoperability with hardware you own, without warranty of any kind.

tests/test_public_api_contract.py

@@ -472,3 +472,37 @@ def test_contents_links_resolve_to_a_heading_on_the_page():
     assert anchors, "the page should carry a table of contents"
     for anchor in anchors:
         assert anchor in headings, anchor
+
+
+_REPO_ROOT = Path(__file__).resolve().parent.parent
+_REPO_BLOB = "https://github.com/QuiteYellow/SmartThings-Local/blob/main/"
+
+
+def test_readme_links_render_on_pypi_and_on_github():
+    """pyproject sets `readme = "README.md"`, so this file is also the
+    package's PyPI description.
+
+    PyPI renders it standalone with no base URL, so a relative path resolves
+    against pypi.org and 404s. GitHub resolves the same path against the
+    repository, which is why a relative link looks fine in review and is
+    dead on the package page. Links are therefore either absolute or an
+    intra-document anchor.
+    """
+    readme = (_REPO_ROOT / "README.md").read_text()
+    headings = {
+        generate_api_docs._slug(line)
+        for line in readme.splitlines()
+        if line.startswith("#")
+    }
+
+    for target in re.findall(r"\]\(([^)]+)\)", readme):
+        if target.startswith("#"):
+            assert target[1:] in headings, f"README anchor goes nowhere: {target}"
+            continue
+        assert target.startswith(("https://", "http://")), (
+            f"relative README link will not render on PyPI: {target}. "
+            f"Use {_REPO_BLOB}{target}"
+        )
+        if target.startswith(_REPO_BLOB):
+            path = _REPO_ROOT / target[len(_REPO_BLOB):].split("#", 1)[0]
+            assert path.exists(), f"README links to a missing file: {target}"