diff --git a/static_src/shared/converters.js b/static_src/shared/converters.js
new file mode 100644
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+++ b/static_src/shared/converters.js
@@ -0,0 +1,102 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+// Based on: https://source.chromium.org/chromium/infra/infra/+/main:appengine/monorail/project/project_constants.py;l=13
+const PROJECT_NAME_PATTERN = '[a-z0-9][-a-z0-9]*[a-z0-9]';
+const USER_ID_PATTERN = '\\d+';
+
+const PROJECT_MEMBER_NAME_REGEX = new RegExp(
+    `projects/(${PROJECT_NAME_PATTERN})/members/(${USER_ID_PATTERN})`);
+
+const USER_NAME_REGEX = new RegExp(`users/(${USER_ID_PATTERN})`);
+
+const PROJECT_NAME_REGEX = new RegExp(`projects/(${PROJECT_NAME_PATTERN})`);
+
+
+/**
+ * Custom error class for handling invalidly formatted resource names.
+ */
+export class ResourceNameError extends Error {
+  /** @override */
+  constructor(message) {
+    super(message || 'Invalid resource name format');
+  }
+}
+
+/**
+ * Returns a FieldMask given an array of string paths.
+ * https://developers.google.com/protocol-buffers/docs/reference/csharp/class/google/protobuf/well-known-types/field-mask#paths
+ * https://source.chromium.org/chromium/chromium/src/+/main:third_party/protobuf/python/google/protobuf/internal/well_known_types.py;l=425;drc=e10d98917fee771b0947a57468d1cadac446bc42
+ * @param {Array<string>} paths The given paths to turn into a field mask.
+ *   These should be a comma separated list of camel case strings.
+ * @return {string}
+ */
+export function pathsToFieldMask(paths) {
+  return paths.join(',');
+}
+
+/**
+ * Extract a User ID from a User resource name.
+ * @param {UserName} user User resource name.
+ * @return {string} User ID.
+ * @throws {Error} if the User resource name is invalid.
+ */
+export function extractUserId(user) {
+  const matches = user.match(USER_NAME_REGEX);
+  if (!matches) {
+    throw new ResourceNameError();
+  }
+  return matches[1];
+}
+
+/**
+ * Extract a project's displayName from a Project resource name.
+ * @param {ProjectName} project Project resource name.
+ * @return {string} The project's displayName.
+ * @throws {Error} if the Project resource name is invalid.
+ */
+export function extractProjectDisplayName(project) {
+  const matches = project.match(PROJECT_NAME_REGEX);
+  if (!matches) {
+    throw new ResourceNameError();
+  }
+  return matches[1];
+}
+
+/**
+ * Gets the displayName of the Project referenced in a ProjectMember
+ * resource name.
+ * @param {ProjectMemberName} projectMember ProjectMember resource name.
+ * @return {string} A display name for a project.
+ */
+export function extractProjectFromProjectMember(projectMember) {
+  const matches = projectMember.match(PROJECT_MEMBER_NAME_REGEX);
+  if (!matches) {
+    throw new ResourceNameError();
+  }
+  return matches[1];
+}
+
+/**
+ * Creates a ProjectStar resource name based on a UserName nad a ProjectName.
+ * @param {ProjectName} project Resource name of the referenced project.
+ * @param {UserName} user Resource name of the referenced user.
+ * @return {ProjectStarName}
+ * @throws {Error} If the project or user resource name is invalid.
+ */
+export function projectAndUserToStarName(project, user) {
+  if (!project || !user) return undefined;
+  const userId = extractUserId(user);
+  const projectName = extractProjectDisplayName(project);
+  return `users/${userId}/projectStars/${projectName}`;
+}
+
+/**
+ * Converts a given ProjectMemberName to just the ProjectName segment present.
+ * @param {ProjectMemberName} projectMember Resource name of a ProjectMember.
+ * @return {ProjectName} Resource name of the referenced project.
+ */
+export function projectMemberToProjectName(projectMember) {
+  const project = extractProjectFromProjectMember(projectMember);
+  return `projects/${project}`;
+}