Fix excmd completion not working with nested aliases

src/aliases.ts

@@ -34,3 +34,42 @@ export function expandExstr(
         prevExpansions,
     )
 }
+
+/**
+ * Get all aliases for all commands.
+ *
+ * @param aliases An object mapping aliases to commands
+ * @return commands An object mapping commands to an array of aliases
+ */
+export function getCmdAliasMapping(
+    aliases = config.get("exaliases"),
+): { [str: string]: string[] } {
+    let commands = {}
+    // aliases look like this: {alias: command} but what we really need is this: {command: [alias1, alias2...]}
+    // This is what this loop builds
+    for (let alias in aliases) {
+        let cmd = aliases[alias].trim()
+        if (!commands[cmd]) commands[cmd] = []
+        commands[cmd].push(alias.trim())
+    }
+    // Some aliases might be aliases to other aliases (e.g. colors -> colourscheme -> set theme) so we need to recursively resolve them
+    function getAliases(cmd: string, prevExpansions: string[]): string[] {
+        if (!commands[cmd]) return []
+        if (prevExpansions.includes(cmd))
+            throw `Infinite loop detected while expanding aliases. Stack: ${prevExpansions}.`
+        return commands[cmd]
+            .reduce(
+                (result, alias) =>
+                    result.concat(
+                        getAliases(alias, prevExpansions.concat(cmd)),
+                    ),
+                [],
+            )
+            .concat(commands[cmd])
+    }
+    let result = {}
+    for (let cmd in commands) {
+        result[cmd] = getAliases(cmd, [])
+    }
+    return result
+}

src/completions.ts

@@ -14,6 +14,7 @@ import * as Fuse from "fuse.js"
 import { enumerate } from "./itertools"
 import { toNumber } from "./convert"
 import * as config from "./config"
+import * as aliases from "./aliases"
 
 export const DEFAULT_FAVICON = browser.extension.getURL(
     "static/defaultFavicon.svg",
@@ -37,15 +38,7 @@ export abstract class CompletionSource {
     protected prefixes: string[] = []
 
     constructor(prefixes) {
-        let exaliases = config.get("exaliases")
-        let commands = {}
-        // exaliases look like this: {alias: command} but what we really need is this: {command: [alias1, alias2...]}
-        // This is what this loop builds
-        for (let alias in exaliases) {
-            let cmd = exaliases[alias]
-            if (!commands[cmd]) commands[cmd] = []
-            commands[cmd].push(alias)
-        }
+        let commands = aliases.getCmdAliasMapping()
 
         // Now, for each prefix given as argument, add it to the completionsource's prefix list and also add any alias it has
         prefixes.map(p => p.trim()).forEach(p => {