feat(bazel): extract types from ts_project targets (#2912)

Look for types and transitive types in JsInfo provider.

PR Close #2912

Author: josephperrott

bazel/extract_types_rjs.bzl

@@ -0,0 +1,35 @@
+load("@aspect_rules_js//js:providers.bzl", "JsInfo")
+
+def _extract_types_impl(ctx):
+    """Implementation of the `extract_types` rule."""
+    depsets = []
+
+    for dep in ctx.attr.deps:
+        if JsInfo in dep:
+            depsets.append(dep[JsInfo].transitive_types)
+            depsets.append(dep[JsInfo].types)
+
+    types = depset(transitive = depsets)
+
+    return [
+        DefaultInfo(files = types),
+    ]
+
+extract_types = rule(
+    implementation = _extract_types_impl,
+    doc = """
+      Rule that collects all direct and transitive type definitions of specified targets. The
+      definitons are then exposed through the `DefaultInfo` provider, allowing for easy
+      consumption in other rules.
+
+      This rule can be helpful if TypeScript typings are shipped along with bundled runtime code.
+    """,
+    attrs = {
+        "deps": attr.label_list(
+            doc = """List of targets for which all direct and transitive type definitions
+              should be collected.""",
+            allow_files = True,
+            mandatory = True,
+        ),
+    },
+)