Bug 1814266 - Migrate strings after removing learn more markup. r=fluent-reviewers,flod

Depends on D173701

Differential Revision: https://phabricator.services.mozilla.com/D174759

python/l10n/fluent_migrations/bug_1814266_identity_custom_root.py

@@ -0,0 +1,34 @@
+# Any copyright is dedicated to the Public Domain.
+# http://creativecommons.org/publicdomain/zero/1.0/
+
+import fluent.syntax.ast as FTL
+
+from fluent.migrate.transforms import TransformPattern
+
+
+class STRIP_LEARNMORE(TransformPattern):
+    # Used to remove `<a data-l10n-name="link">SOME TEXT</a>` from a string
+    def visit_TextElement(self, node):
+        link_start = node.value.find('<label data-l10n-name="link">')
+        # Replace string up to the link, remove remaining spaces afterwards.
+        # Removing an extra character directly is not safe, as it could be
+        # punctuation.
+        node.value = node.value[:link_start].rstrip()
+
+        return node
+
+
+def migrate(ctx):
+    """Bug 1814266 - Use moz-support-link in identity panel, part {index}."""
+
+    browser_ftl = "browser/browser/browser.ftl"
+    ctx.add_transforms(
+        browser_ftl,
+        browser_ftl,
+        [
+            FTL.Message(
+                id=FTL.Identifier("identity-description-custom-root2"),
+                value=STRIP_LEARNMORE(browser_ftl, "identity-description-custom-root"),
+            ),
+        ],
+    )