feat: optional conf.py

BUILD

@@ -14,9 +14,14 @@
 load("//:docs.bzl", "docs")
 
 package(default_visibility = ["//visibility:public"])
-exports_files(["pyproject.toml"])
+exports_files([
+    "default_conf.py.tpl",
+    "pyproject.toml",
+])
 
 docs(
+    project = "S-CORE Docs-as-Code",
+    project_url = "https://eclipse-score.github.io/docs-as-code",
     external_needs = [
         "@score_process//:needs_json_file",
     ],

src/tests/docs_bzl/scenarios/basic_docs/docs/conf.py → default_conf.py.tpl

@@ -10,7 +10,11 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
+# Default Sphinx configuration emitted by the ``docs()`` macro.
+# SCORE Docs-as-Code owns these baseline settings.  Projects needing further
+# Sphinx configuration can provide their own conf.py instead.
+
+project = {PROJECT}
+project_url = {PROJECT_URL}
 
-project = "Basic Test"
-project_url = "https://github.com/eclipse-score/docs-as-code"
 extensions = ["score_sphinx_bundle"]

docs.bzl

@@ -61,6 +61,31 @@ load(
     "create_mounts_manifest",
 )
 
+def _generated_conf_impl(ctx):
+    output = ctx.actions.declare_file(ctx.attr.output_path)
+    ctx.actions.expand_template(
+        template = ctx.file.template,
+        output = output,
+        substitutions = {
+            "{PROJECT}": repr(ctx.attr.project),
+            "{PROJECT_URL}": repr(ctx.attr.project_url),
+        },
+    )
+    return [DefaultInfo(files = depset([output]))]
+
+_generated_conf = rule(
+    implementation = _generated_conf_impl,
+    attrs = {
+        "project": attr.string(mandatory = True),
+        "project_url": attr.string(mandatory = True),
+        "output_path": attr.string(mandatory = True),
+        "template": attr.label(
+            allow_single_file = True,
+            default = Label("@score_docs_as_code//:default_conf.py.tpl"),
+        ),
+    },
+)
+
 def docs_bundle(name, source_dir = None, data = [], entry_doc = "index", bundles = [], scan_code = [], code_targets = [], visibility = None, **kwargs):
     """A docs bundle, optionally composed of others.
 
@@ -154,6 +179,8 @@ def _missing_requirements(deps):
 
 def docs(
         source_dir = "docs",
+        project = None,
+        project_url = None,
         data = [],
         deps = [],
         external_needs = [],
@@ -170,6 +197,8 @@ def docs(
 
     Args:
       source_dir: The source directory containing documentation files. Defaults to "docs".
+      project: optional project name, prefer setting this here if you can avoid having a conf.py
+      project_url: Optional project URL, prefer setting this here if you can avoid having a conf.py
       data: Additional data files to include in the documentation build.
       deps: Additional dependencies for the documentation build.
       external_needs: List of external needs targets to include in the documentation build.
@@ -195,7 +224,23 @@ def docs(
     """
     # HINT: keep documentation sync docs/reference/bazel_macros.rst
 
-    source_config = ":" + ("" if source_dir == "." else source_dir + "/") + "conf.py"
+    config_file_path = join_path(source_dir, "conf.py")
+    sphinx_config = ":" + config_file_path
+    config_is_generated = len(native.glob([config_file_path], allow_empty = True)) == 0
+
+    if config_is_generated:
+        if not project or not project_url:
+            fail("docs(): no " + config_file_path + " found; provide both project and project_url to docs().")
+        # Generate the config at the source-root location expected by
+        # sphinx_docs: that rule treats the config file's directory as the
+        # Sphinx source directory.
+        _generated_conf(
+            name = "_docs_generated_config",
+            project = project,
+            project_url = project_url,
+            output_path = config_file_path,
+        )
+        sphinx_config = ":_docs_generated_config"
 
     # Convention in this macro: an optional Bazel label is named ``*_label``
     # but represented as a 0/1 list. This lets it be appended directly to
@@ -256,11 +301,18 @@ def docs(
         visibility = ["//visibility:private"],
     )
 
-    # ``bazel run`` reads local documentation from the workspace. Passing the
-    # complete bundle here would add those files to runfiles and could collide
-    # with the executable target name (for example ``docs`` and ``docs/``).
-    # External bundles do need runfiles, so keep only those sources.
-    docs_data = data + external_needs + metamodel_label + [":sourcelinks_json", ":_external_docs_runfiles"] + mounts_manifest_label
+    # ``bazel run`` reads local documentation from the workspace, so including
+    # the complete bundle in runfiles would duplicate those sources. External
+    # bundles do need runfiles, so keep only those sources.
+    docs_data = (
+        data + external_needs + metamodel_label +
+        [":sourcelinks_json", ":_external_docs_runfiles"] +
+        mounts_manifest_label
+    )
+    if config_is_generated:
+        # A source configuration is read from the workspace; only the
+        # generated configuration must be present in the runfiles tree.
+        docs_data += [sphinx_config]
 
     docs_env = {
         "SOURCE_DIRECTORY": source_dir,
@@ -273,6 +325,10 @@ def docs(
         "MOUNTS_MANIFEST": "$(rlocationpath :_mounts_manifest)" if bundles else "",
         "SCORE_SOURCELINKS": "$(location :sourcelinks_json)",
     }
+    if config_is_generated:
+        # The generated file is named conf.py. Run targets pass its containing
+        # directory to Sphinx via -c.
+        docs_env["SPHINX_CONFIG_FILE"] = "$(rlocationpath " + sphinx_config + ")"
     if metamodel:
         # The interactive ``py_binary`` targets run from a runfiles tree.
         # incremental.py resolves this logical path through ``RUNFILES_DIR``.
@@ -285,14 +341,22 @@ def docs(
     docs_env["ACTION"] = "incremental"
 
     py_binary(
-        name = "docs",
-        tags = ["cli_help=Build documentation:\nbazel run //:docs"],
+        # Generated documentation artifacts may live below ``docs/``.  A
+        # py_binary named ``docs`` would own the conflicting Bazel output path
+        # ``docs``; expose this binary via the alias below instead.
+        name = "_score_docs_cli",
         srcs = [incremental_src],
         data = docs_data,
         deps = deps,
         env = docs_env
     )
 
+    native.alias(
+        name = "docs",
+        actual = ":_score_docs_cli",
+        tags = ["cli_help=Build documentation:\nbazel run //:docs"],
+    )
+
     docs_env["ACTION"] = "linkcheck"
     py_binary(
         name = "docs_link_check",
@@ -335,7 +399,7 @@ def docs(
     sphinx_docs(
         name = "needs_json",
         srcs = [":docs_bundle"],
-        config = source_config,
+        config = sphinx_config,
         extra_opts = [
             "-W",
             "--keep-going",

docs/how-to/setup.md

@@ -67,6 +67,8 @@ load("@score_docs_as_code//:docs.bzl", "docs")
 
 docs(
     source_dir = "<your sphinx source dir>",
+    project = "<your project name>",
+    project_url = "https://github.com/eclipse-score/<your-project>",
     data = [
         "@other_repo:needs_json",  # Optional, if you have dependencies
     ],
@@ -75,10 +77,20 @@ docs(
 
 For configuration options see {ref}`docs_bazel-macros`.
 
-### 4. Copy conf.py
+### 4. Optional: add conf.py
 
-Copy the `conf.py` file from the `docs-as-code` module to your `source_dir`.
+No `conf.py` is required for the default setup. The `docs()` macro generates
+one from `project` and `project_url`; the Docs-as-Code version and baseline
+extensions are supplied automatically.
 
+Add a `conf.py` to your source directory only when you need additional Sphinx
+configuration. When it exists, it remains the authoritative configuration.
+
+A custom `conf.py` applies to this repository's documentation targets. Its
+effect on integrated documentation depends on the integration path: it affects
+the exported `:needs_json`, but is not transferred when documentation sources
+are mounted as a bundle, where the host configuration applies. Keep custom
+configuration minimal.
 
 #### 5. Run a documentation build:
 

docs/reference/bazel_macros.rst

@@ -34,6 +34,8 @@ Minimal example (root ``BUILD``)
 
    docs(
        source_dir = "docs",
+       project = "My Project",
+       project_url = "https://github.com/eclipse-score/my-project",
        data = [
            # labels to any extra tools or data you want included
            # e.g. "//:needs_json" or other tool targets
@@ -49,7 +51,13 @@ Minimal example (root ``BUILD``)
 
 - ``source_dir`` (string, default: ``"docs"``)
   Path (relative to repository root) to your Sphinx source directory. This is the folder
-  that contains your ``conf.py`` and the top-level ReST/markdown sources.
+  that contains the top-level ReST/markdown sources. A ``conf.py`` is optional.
+
+- ``project`` and ``project_url`` (strings, optional)
+  Project name and canonical project URL. They are required when ``source_dir``
+  has no ``conf.py``; in that case ``docs()`` generates the Sphinx configuration
+  and supplies the Docs-as-Code baseline version and extensions. If a ``conf.py``
+  exists, it remains authoritative and these values are not used.
 
 - ``data`` (list of bazel labels)
   Extra runfiles / data targets that should be made available to the documentation targets.

src/extensions/score_sphinx_bundle/__init__.py

@@ -10,6 +10,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 # *******************************************************************************
+import matplotlib
 from sphinx.application import Sphinx
 
 from src.helper_lib import config_setdefault
@@ -42,6 +43,8 @@
 
 
 def setup(app: Sphinx) -> dict[str, object]:
+    matplotlib.rcParamsDefault["savefig.bbox"] = "tight"
+
     config_setdefault(app.config, "html_copy_source", False)
     config_setdefault(app.config, "html_show_sourcelink", False)
 

src/incremental.py

@@ -165,6 +165,15 @@ def _mounted_watch_dirs(
         f"--define=mounts_manifest={os.environ.get('MOUNTS_MANIFEST', '')}",
     ]
 
+    generated_config = os.environ.get("SPHINX_CONFIG_FILE", "")
+    if generated_config:
+        # Under ``bazel run`` this is a runfiles-relative path.  Sphinx wants
+        # the directory containing a file literally named ``conf.py``.
+        config_file = Path(generated_config)
+        if not config_file.is_absolute():
+            config_file = get_runfiles_dir() / config_file
+        base_arguments.extend(["-c", str(config_file.parent)])
+
     metamodel_yaml = os.environ.get("SCORE_METAMODEL_YAML", "")
     if metamodel_yaml:
         # ``docs`` passes a runfiles-relative path under ``bazel run``.  Keep

src/tests/docs_bzl/scenarios/basic_docs/BUILD

@@ -15,5 +15,7 @@ load("//:docs.bzl", "docs")
 
 docs(
     source_dir = "docs",
+    project = "Basic Test",
+    project_url = "https://github.com/eclipse-score/docs-as-code",
     test_sources = ["src/tests/docs_bzl/scenarios/basic_docs"],
 )

src/tests/docs_bzl/scenarios/missing_docs_config/BUILD.negative

@@ -0,0 +1,12 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+
+load("//:docs.bzl", "docs")
+
+docs(source_dir = "docs")

src/tests/docs_bzl/scenarios/missing_docs_config/docs/index.rst

@@ -0,0 +1,16 @@
+..
+   # *******************************************************************************
+   # Copyright (c) 2026 Contributors to the Eclipse Foundation
+   #
+   # See the NOTICE file(s) distributed with this work for additional
+   # information regarding copyright ownership.
+   #
+   # This program and the accompanying materials are made available under the
+   # terms of the Apache License Version 2.0 which is available at
+   # https://www.apache.org/licenses/LICENSE-2.0
+   #
+   # SPDX-License-Identifier: Apache-2.0
+   # *******************************************************************************
+
+Missing configuration fixture
+=============================

src/tests/docs_bzl/test_basic_docs.py

@@ -32,3 +32,7 @@ def test_basic_docs_builds_html():
     index_html = result.build_dir / "index.html"
 
     assert "Basic Test" in index_html.read_text(encoding="utf-8")
+
+
+def test_basic_docs_builds_needs_without_conf_py():
+    run_scenario("build", "basic_docs", ":needs_json")

src/tests/docs_bzl/test_missing_docs_config.py

@@ -0,0 +1,31 @@
+# *******************************************************************************
+# Copyright (c) 2026 Contributors to the Eclipse Foundation
+#
+# See the NOTICE file(s) distributed with this work for additional
+# information regarding copyright ownership.
+#
+# SPDX-License-Identifier: Apache-2.0
+# *******************************************************************************
+"""Validation of docs() configuration fallback."""
+
+from src.tests.docs_bzl.helpers import repo_root, run_scenario
+
+
+def test_missing_conf_and_macro_values_fails_analysis():
+    scenario_dir = repo_root() / "src/tests/docs_bzl/scenarios/missing_docs_config"
+    build_file = scenario_dir / "BUILD"
+    fixture = scenario_dir / "BUILD.negative"
+    assert not build_file.exists(), (
+        "negative test package must not be discovered by //..."
+    )
+
+    build_file.write_text(fixture.read_text(encoding="utf-8"), encoding="utf-8")
+    try:
+        result = run_scenario(
+            "build", "missing_docs_config", ":docs", expect_error=True
+        )
+    finally:
+        build_file.unlink()
+
+    assert "no docs/conf.py found" in result.stderr
+    assert "provide both project and project_url" in result.stderr