IJI-3418 build scripts: Bazel: watch for the entire JPS project model to correctly re-run generator on any change

GitOrigin-RevId: 29171ca937e5ec4bf7bee4b9597ebf26b08d83cc

MODULE.bazel.lock

@@ -325,7 +325,7 @@
     },
     "//build:jps_dynamic_deps_community.bzl%jps_dynamic_deps_community_extension": {
       "general": {
-        "bzlTransitiveDigest": "3xhuyu/RwZY46XM2F9PzxVuqXwuOnK9XPrCPpt/gKTI=",
+        "bzlTransitiveDigest": "3CitlyO8eztna/EextdwgGkMSx42lDg2RITKuKTLH0U=",
         "usagesDigest": "OSsQY2hkpxdAkgfVzTh+Q1KLtzAuQDVI0/8sRki7FfU=",
         "recordedFileInputs": {},
         "recordedDirentsInputs": {},

build/jps_dynamic_deps_community.bzl

@@ -36,6 +36,8 @@ STALENESS & WATCHING:
 This repository is invalidated on changes to `.idea/modules.xml` via ctx.watch().
 """
 
+load(":jps_model.bzl", "watch_project_model_files")
+
 def _format_target_list(name, targets):
     """Format a list of targets as a Starlark list assignment."""
     if not targets:
@@ -60,11 +62,8 @@ def _targets_repo_impl(ctx):
     # SETUP CONTEXT AND WATCHER
     root = ctx.path(Label("@community//:MODULE.bazel")).dirname
 
-    # we set watcher on .idea/modules.xml, because we only need to regenerate targets' list if a new module was added
-    # otherwise the list get populated on import and bazel clean invalidates it anyway
-    idea_dir = root.get_child(".idea")
-    modules_xml = idea_dir.get_child("modules.xml")
-    ctx.watch(modules_xml)
+    # Watch the entire model to re-run generator on changes
+    watch_project_model_files(ctx, root)
 
     script = (
         root

build/jps_model.bzl

@@ -0,0 +1,42 @@
+def _parse_project_relative_module_paths_strict(modules_xml_text):
+    marker = 'filepath="'
+    prefix = "$PROJECT_DIR$/"
+
+    rels = []
+    i = 0
+
+    # Upper bound: you can't have more attributes than characters.
+    for _ in range(len(modules_xml_text) + 1):
+        j = modules_xml_text.find(marker, i)
+        if j == -1:
+            break
+
+        j += len(marker)
+        k = modules_xml_text.find('"', j)
+        if k == -1:
+            fail("Malformed XML: unterminated filepath attribute (missing closing quote)")
+
+        full = modules_xml_text[j:k]
+        if not full.startswith(prefix):
+            fail("Unexpected module filepath (expected to start with %r): %r" % (prefix, full))
+
+        rels.append(full[len(prefix):])
+        i = k + 1
+
+    if not rels:
+        fail("No module filepaths found")
+
+    return rels
+
+def watch_project_model_files(ctx, project_root):
+    idea_dir = project_root.get_child(".idea")
+    modules_xml = idea_dir.get_child("modules.xml")
+
+    # Read (to make sure it exists) and watch all modules to re-run generator on changes
+    for relativeModulePath in _parse_project_relative_module_paths_strict(ctx.read(modules_xml, watch='yes')):
+        ctx.read(project_root.get_child(relativeModulePath), watch='yes')
+
+    # Read (to make sure it exists) and watch all libraries under .idea/libraries to re-run generator on changes
+    libraries_dir = idea_dir.get_child("libraries")
+    for library_xml in libraries_dir.readdir(watch='yes'):
+        ctx.read(library_xml, watch='yes')