docs: Linked reference docs to source code (#2239)

docs: Link to source code

Closes #149

docs/conf.py

@@ -12,6 +12,7 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
+from __future__ import annotations
 
 import sys
 from pathlib import Path
@@ -29,7 +30,7 @@
 release = "0.35.0"
 
 
-# -- General configuration ---------------------------------------------------
+# -- General configuration -------------------------------------------------------------
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
@@ -40,6 +41,7 @@
     "sphinx.ext.autosectionlabel",
     "sphinx.ext.autosummary",
     "sphinx.ext.intersphinx",
+    "sphinx.ext.linkcode",
     "sphinx_copybutton",
     "myst_parser",
     "sphinx_reredirects",
@@ -55,12 +57,7 @@
 # This pattern also affects html_static_path and html_extra_path.
 exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
-# Show typehints in the description, along with parameter descriptions
-autodoc_typehints = "description"
-autodoc_class_signature = "separated"
-autodoc_member_order = "groupwise"
-
-# -- Options for HTML output -------------------------------------------------
+# -- Options for HTML output -----------------------------------------------------------
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
@@ -118,7 +115,19 @@
     "css/custom.css",
 ]
 
-# -- Options for MyST --------------------------------------------------------
+# -- Options for AutoDoc ---------------------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/extensions/autodoc.html#configuration
+
+# Show typehints in the description
+autodoc_typehints = "description"
+
+# Display the signature as a method.
+autodoc_class_signature = "separated"
+
+# Sort members by type.
+autodoc_member_order = "groupwise"
+
+# -- Options for MyST ------------------------------------------------------------------
 # https://myst-parser.readthedocs.io/en/latest/configuration.html
 myst_heading_anchors = 3
 myst_enable_extensions = {
@@ -129,9 +138,34 @@
     "porting.html": "guides/porting.html",
 }
 
-# -- Options for intersphinx -------------------------------------------------
+# -- Options for intersphinx -----------------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/extensions/intersphinx.html#configuration
 intersphinx_mapping = {
     "requests": ("https://requests.readthedocs.io/en/latest/", None),
     "python": ("https://docs.python.org/3/", None),
 }
+
+# -- Options for linkcode --------------------------------------------------------------
+# https://www.sphinx-doc.org/en/master/usage/extensions/linkcode.html#configuration
+
+
+def linkcode_resolve(domain: str, info: dict) -> str | None:
+    """Get URL to source code.
+
+    Args:
+        domain: Language domain the object is in.
+        info: A dictionary with domain-specific keys.
+
+    Returns:
+        A URL.
+    """
+    if domain != "py":
+        return None
+    if not info["module"]:
+        return None
+    filename = info["module"].replace(".", "/")
+
+    if filename == "singer_sdk":
+        filename = "singer_sdk/__init__"
+
+    return f"https://github.com/meltano/sdk/tree/main/{filename}.py"