Editor: Refactor dirtiness condition on pending transactions

editor/store/selectors.js

@@ -89,7 +89,7 @@ export function isEditedPostNew( state ) {
  * @return {boolean} Whether unsaved values exist.
  */
 export function isEditedPostDirty( state ) {
-	return state.editor.isDirty || isSavingPost( state );
+	return state.editor.isDirty || inSomeHistory( state, isEditedPostDirty );
 }
 
 /**
@@ -1568,3 +1568,25 @@ export function getPermalinkParts( state ) {
 		suffix,
 	};
 }
+
+/**
+ * Returns true if an optimistic transaction is pending commit, for which the
+ * before state satisfies the given predicate function.
+ *
+ * @param {Object}   state     Editor state.
+ * @param {Function} predicate Function given state, returning true if match.
+ *
+ * @return {boolean} Whether predicate matches for some history.
+ */
+export function inSomeHistory( state, predicate ) {
+	const { optimist } = state;
+
+	// In recursion, optimist state won't exist. Assume exhausted options.
+	if ( ! optimist ) {
+		return false;
+	}
+
+	return optimist.some( ( { beforeState } ) => (
+		beforeState && predicate( beforeState )
+	) );
+}

editor/store/test/selectors.js

@@ -212,14 +212,20 @@ describe( 'selectors', () => {
 			expect( isEditedPostDirty( state ) ).toBe( true );
 		} );
 
-		it( 'should return true if mid-save', () => {
+		it( 'should return true if pending transaction with dirty state', () => {
 			const state = {
+				optimist: [
+					{
+						beforeState: {
+							editor: {
+								isDirty: true,
+							},
+						},
+					},
+				],
 				editor: {
 					isDirty: false,
 				},
-				saving: {
-					requesting: true,
-				},
 			};
 
 			expect( isEditedPostDirty( state ) ).toBe( true );