format: Fix dropped with-clause after comment in object value (#8785)

resolve: https://github.com/open-policy-agent/opa/issues/8765

Signed-off-by: Sebastian Spaink <sebastianspaink@gmail.com>

v1/format/format.go

@@ -1212,7 +1212,13 @@ func (w *writer) writeWith(with *ast.With, comments []*ast.Comment, indented boo
 	w.write(" as ")
 	comments, err = w.writeTerm(with.Value, comments)
 	if err != nil {
-		return comments, err
+		// An unexpectedCommentError from writeTerm signals that it fell
+		// back to writing the term's original unformatted text — the value
+		// was written successfully, so don't abort the surrounding chain
+		// of `with` clauses (issue #8765).
+		if !errors.As(err, &unexpectedCommentError{}) {
+			return comments, err
+		}
 	}
 	return comments, nil
 }

v1/format/testfiles/v1/test_issue_8765_with_after_object_comment.rego

@@ -0,0 +1,9 @@
+package test
+
+test_x if {
+	r := allow with input as {
+		"a": "b", # a comment
+	}
+	with opa.runtime as {"env": {"E": "PROD"}}
+	r == false
+}

v1/format/testfiles/v1/test_issue_8765_with_after_object_comment.rego.formatted

@@ -0,0 +1,9 @@
+package test
+
+test_x if {
+	r := allow with input as {
+		"a": "b", # a comment
+	}
+		with opa.runtime as {"env": {"E": "PROD"}}
+	r == false
+}