Make src/shared/ typecheck when `noImplicitAny` is set

Fix various errors and omissions found when TypeScript's `noImplicitAny`
option is enabled.

src/shared/messaging/port-rpc.js

@@ -55,7 +55,7 @@ const PROTOCOL = 'frame-rpc';
  *
  * @param {MessagePort} port
  * @param {string} method
- * @param {any[]} [arguments]
+ * @param {any[]} [args]
  * @param {number} [sequence] - Sequence number used for replies
  */
 function sendCall(port, method, args = [], sequence = -1) {

src/shared/prompts.js

@@ -12,9 +12,9 @@ import { ConfirmModal } from '@hypothesis/frontend-shared';
  *  - The visual style of the dialog matches the Hypothesis design system
  *
  * @param {object} options - Options for the `ConfirmModal`
- *   @prop {string} [title]
- *   @prop {string} message
- *   @prop {string} [confirmAction]
+ *   @param {string} [options.title]
+ *   @param {string} options.message
+ *   @param {string} [options.confirmAction]
  * @return {Promise<boolean>} - Promise that resolves with `true` if the user
  *   confirmed the action or `false` if they canceled it.
  */

src/shared/random.js

+/** @param {number} val */
 function byteToHex(val) {
   const str = val.toString(16);
   return str.length === 1 ? '0' + str : str;

src/shared/renderer-options.js

@@ -4,7 +4,7 @@ import { options } from 'preact';
  * Setup workarounds for setting certain HTML element properties or attributes
  * in some browsers.
  *
- * @param {object} _options - Test seam
+ * @param {import('preact').Options} _options - Test seam
  */
 export function setupBrowserFixes(_options = options) {
   let needsDirAutoFix = false;
@@ -21,9 +21,10 @@ export function setupBrowserFixes(_options = options) {
     const prevHook = _options.vnode;
     _options.vnode = vnode => {
       if (typeof vnode.type === 'string') {
-        if ('dir' in vnode.props && vnode.props.dir === 'auto') {
+        const props = /** @type {{ dir?: string }} */ (vnode.props);
+        if ('dir' in props && props.dir === 'auto') {
           // Re-assign `vnode.props.dir` if its value is "auto"
-          vnode.props.dir = '';
+          props.dir = '';
         }
       }
       // Call previously defined hook if there was any

src/shared/shortcut.js

@@ -2,7 +2,11 @@ import { normalizeKeyName } from '@hypothesis/frontend-shared';
 
 import { useEffect } from 'preact/hooks';
 
-// Bit flags indicating modifiers required by a shortcut or pressed in a key event.
+/**
+ * Bit flags indicating modifiers required by a shortcut or pressed in a key event.
+ *
+ * @type {Record<string, number>}
+ */
 const modifiers = {
   alt: 1,
   ctrl: 2,
@@ -78,6 +82,7 @@ export function installShortcut(
   onPress,
   { rootElement = document.body } = {}
 ) {
+  /** @param {KeyboardEvent} event */
   const onKeydown = event => {
     if (matchShortcut(event, shortcut)) {
       onPress(event);

src/shared/warn-once.js

-let shownWarnings = {};
+/** @type {Set<string>} */
+let shownWarnings = new Set();
 
 /**
  * Log a warning if it has not already been reported.
@@ -13,13 +14,13 @@ let shownWarnings = {};
  */
 export function warnOnce(...args) {
   const key = args.join();
-  if (key in shownWarnings) {
+  if (shownWarnings.has(key)) {
     return;
   }
   console.warn(...args);
-  shownWarnings[key] = true;
+  shownWarnings.add(key);
 }
 
 warnOnce.reset = () => {
-  shownWarnings = {};
+  shownWarnings.clear();
 };