Implement tab-complete for slash commands

This needed a new interface function `getOverrideSuffix()` so we didn't suffix
commands at the start with ": ". All seems to work.

src/SlashCommands.js

@@ -322,5 +322,11 @@ module.exports = {
             }
         }
         return null; // not a command
+    },
+
+    getCommandList: function() {
+        return Object.keys(commands).map(function(cmd) {
+            return "/" + cmd;
+        });
     }
 };

src/TabComplete.js

@@ -58,7 +58,7 @@ class TabComplete {
             // assign onClick listeners for each entry to complete the text
             this.list.forEach((l) => {
                 l.onClick = () => {
-                    this.completeTo(l.getText());
+                    this.completeTo(l);
                 }
             });
         }
@@ -93,10 +93,10 @@ class TabComplete {
 
     /**
      * Do an auto-complete with the given word. This terminates the tab-complete.
-     * @param {string} someVal
+     * @param {Entry} entry The tab-complete entry to complete to.
      */
-    completeTo(someVal) {
-        this.textArea.value = this._replaceWith(someVal, true);
+    completeTo(entry) {
+        this.textArea.value = this._replaceWith(entry.getText(), true, entry.getOverrideSuffix());
         this.stopTabCompleting();
         // keep focus on the text area
         this.textArea.focus();
@@ -222,8 +222,9 @@ class TabComplete {
         if (!this.inPassiveMode) {
             // set textarea to this new value
             this.textArea.value = this._replaceWith(
-                this.matchedList[this.currentIndex].text,
-                this.currentIndex !== 0 // don't suffix the original text!
+                this.matchedList[this.currentIndex].getText(),
+                this.currentIndex !== 0, // don't suffix the original text!
+                this.matchedList[this.currentIndex].getOverrideSuffix()
             );
         }
 
@@ -243,7 +244,7 @@ class TabComplete {
         }
     }
 
-    _replaceWith(newVal, includeSuffix) {
+    _replaceWith(newVal, includeSuffix, overrideSuffix) {
         // The regex to replace the input matches a character of whitespace AND
         // the partial word. If we just use string.replace() with the regex it will
         // replace the partial word AND the character of whitespace. We want to
@@ -258,13 +259,17 @@ class TabComplete {
             boundaryChar = "";
         }
 
-        var replacementText = (
-            boundaryChar + newVal + (
-                includeSuffix ?
-                    (this.isFirstWord ? this.opts.startingWordSuffix : this.opts.wordSuffix) :
-                    ""
-            )
-        );
+        var suffix = "";
+        if (includeSuffix) {
+            if (overrideSuffix) {
+                suffix = overrideSuffix;
+            }
+            else {
+                suffix = (this.isFirstWord ? this.opts.startingWordSuffix : this.opts.wordSuffix);
+            }
+        }
+
+        var replacementText = boundaryChar + newVal + suffix;
         return this.originalText.replace(MATCH_REGEX, function() {
             return replacementText; // function form to avoid `$` special-casing
         });

src/TabCompleteEntries.js

@@ -42,6 +42,14 @@ class Entry {
         return null;
     }
 
+    /**
+     * @return {?string} The suffix to override whatever the default is, or null to
+     * not do this.
+     */
+    getOverrideSuffix() {
+        return null;
+    }
+
     /**
      * Called when this entry is clicked.
      */
@@ -50,6 +58,26 @@ class Entry {
     }
 }
 
+class CommandEntry extends Entry {
+    constructor(command) {
+        super(command);
+    }
+
+    getKey() {
+        return this.getText();
+    }
+
+    getOverrideSuffix() {
+        return " "; // force a space after the command.
+    }
+}
+
+CommandEntry.fromStrings = function(commandArray) {
+    return commandArray.map(function(cmd) {
+        return new CommandEntry(cmd);
+    });
+}
+
 class MemberEntry extends Entry {
     constructor(member) {
         super(member.name || member.userId);
@@ -99,3 +127,4 @@ MemberEntry.fromMemberList = function(members) {
 
 module.exports.Entry = Entry;
 module.exports.MemberEntry = MemberEntry;
+module.exports.CommandEntry = CommandEntry;

src/components/structures/RoomView.js

@@ -35,7 +35,9 @@ var sdk = require('../../index');
 var CallHandler = require('../../CallHandler');
 var TabComplete = require("../../TabComplete");
 var MemberEntry = require("../../TabCompleteEntries").MemberEntry;
+var CommandEntry = require("../../TabCompleteEntries").CommandEntry;
 var Resend = require("../../Resend");
+var SlashCommands = require("../../SlashCommands");
 var dis = require("../../dispatcher");
 var Tinter = require("../../Tinter");
 
@@ -416,7 +418,9 @@ module.exports = React.createClass({
             return;
         }
         this.tabComplete.setCompletionList(
-            MemberEntry.fromMemberList(room.getJoinedMembers())
+            MemberEntry.fromMemberList(room.getJoinedMembers()).concat(
+                CommandEntry.fromStrings(SlashCommands.getCommandList())
+            )
         );
     },