Trim range when formatting so that it excludes leading/trailing spaces

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/components/views/rooms/BasicMessageComposer.tsx

@@ -619,13 +619,14 @@ export default class BasicMessageEditor extends React.Component<IProps, IState>
     }
 
     private onFormatAction = (action: Formatting) => {
-        const range = getRangeForSelection(
-            this.editorRef.current,
-            this.props.model,
-            document.getSelection());
+        const range = getRangeForSelection(this.editorRef.current, this.props.model, document.getSelection());
+        // trim the range as we want it to exclude leading/trailing spaces
+        range.trim();
+
         if (range.length === 0) {
             return;
         }
+
         this.historyManager.ensureLastChangesPushed(this.props.model);
         this.modifiedFlag = true;
         switch (action) {

src/editor/range.ts

@@ -18,6 +18,10 @@ import EditorModel from "./model";
 import DocumentPosition, {Predicate} from "./position";
 import {Part} from "./parts";
 
+const whileSpacePredicate: Predicate = (index, offset, part) => {
+    return part.text[offset] === " ";
+};
+
 export default class Range {
     private _start: DocumentPosition;
     private _end: DocumentPosition;
@@ -35,6 +39,11 @@ export default class Range {
         });
     }
 
+    trim() {
+        this._start = this._start.forwardsWhile(this.model, whileSpacePredicate);
+        this._end = this._end.backwardsWhile(this.model, whileSpacePredicate);
+    }
+
     expandBackwardsWhile(predicate: Predicate) {
         this._start = this._start.backwardsWhile(this.model, predicate);
     }