WIP: add a compat wrapper for browser

src/content.ts

@@ -97,6 +97,7 @@ const itertools = await import("@src/lib/itertools")
 const messaging = await import("@src/lib/messaging")
 const State = await import("@src/state")
 const webext = await import("@src/lib/webext")
+const {default: compatProxy} = await import("@src/lib/compat_proxy")
 const perf = await import("@src/perf")
 const keyseq = await import("@src/lib/keyseq")
 const native = await import("@src/lib/native")
@@ -206,6 +207,7 @@ config.getAsync("preventautofocusjackhammer").then(allowautofocus => {
 })
 ;(window as any).tri = Object.assign(Object.create(null), {
     browserBg: webext.browserBg,
+    compatProxy,
     commandline_content,
     convert,
     config,

src/lib/compat_proxy.ts

@@ -0,0 +1,28 @@
+import { message } from "@src/lib/messaging"
+
+const compatProxy = new Proxy(Object.create(null), {
+    get(target, api) {
+        return new Proxy(
+            {},
+            {
+                get(_, func) {
+                    return (...args) => {
+                        if (typeof browser[api][func] === 'function') {
+                            return browser[api][func](...args)
+                        }
+                        // return Promise.reject(new Error(`browser.${String(api)}.${String(func)} isn't a function`))
+                        // ideally what we want is to use TypeScript's knowledge of browser to create an "empty"
+                        // return value of the same type as the function we're trying to call, but I don't know how to do that
+                        // if function missing, return an empty object of the same type using TypeScript
+
+                        // return ReturnType<typeof browser[api][func]> // can't use api because it's _any_, let's fix one thing at a time
+
+                        // return new ReturnType<typeof browser.runtime.getURL>() // Error: ReturnType refers to a type
+                    }
+                },
+            },
+        )
+    },
+}) as typeof browser
+
+export default compatProxy