From 95aa9dc864289723c1a2c90932f06be7401ef174 Mon Sep 17 00:00:00 2001
From: "alonso.torres" <alonso.torres@kaleidos.net>
Date: Wed, 21 Nov 2018 10:51:09 +0100
Subject: [PATCH] Fixes some edge cases on entity selection

---
 CHANGELOG.md               |  2 ++
 lib/api/DraftUtils.js      | 18 +++++++---
 lib/api/DraftUtils.test.js | 74 ++++++++++++++++++++++++++++----------
 3 files changed, 72 insertions(+), 22 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0ed06e35..82774341 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,8 @@
 
 - Stop unnecessarily calling `onSave` in the editor’s `onBlur` ([#173](https://github.com/springload/draftail/issues/173)).
 - Prevent crash when filtering pasted content whose last block is to be removed (e.g. unsupported image) ([#179](https://github.com/springload/draftail/issues/179)).
+- Prevent crash in `DraftUtils.getEntitySelection`, when the provided entity key isn't valid (undefined, missing) ([#168](https://github.com/springload/draftail/pull/168))
+- Fix entity removal and editing not doing anything when the selection is backwards (right to left) ([#168](https://github.com/springload/draftail/pull/168)).
 
 ### Changed
 
diff --git a/lib/api/DraftUtils.js b/lib/api/DraftUtils.js
index 22b2b9f6..d3a02c62 100644
--- a/lib/api/DraftUtils.js
+++ b/lib/api/DraftUtils.js
@@ -61,9 +61,15 @@ export default {
 
   /**
    * Creates a selection on a given entity in the currently selected block.
+   * Returns the current selection if no entity key is provided, or if the entity could not be found.
    */
   getEntitySelection(editorState, entityKey) {
-    const selectionState = editorState.getSelection();
+    const selection = editorState.getSelection();
+
+    if (!entityKey) {
+      return selection;
+    }
+
     const block = this.getSelectedBlock(editorState);
     let entityRange;
     // https://github.com/jpuri/draftjs-utils/blob/e81c0ae19c3b0fdef7e0c1b70d924398956be126/js/inline.js#L111
@@ -77,9 +83,13 @@ export default {
       },
     );
 
-    return selectionState.merge({
-      anchorOffset: entityRange.start,
-      focusOffset: entityRange.end,
+    if (!entityRange) {
+      return selection;
+    }
+
+    return selection.merge({
+      anchorOffset: selection.isBackward ? entityRange.end : entityRange.start,
+      focusOffset: selection.isBackward ? entityRange.start : entityRange.end,
     });
   },
 
diff --git a/lib/api/DraftUtils.test.js b/lib/api/DraftUtils.test.js
index 84b430d0..2350c13b 100644
--- a/lib/api/DraftUtils.test.js
+++ b/lib/api/DraftUtils.test.js
@@ -152,33 +152,71 @@ describe("DraftUtils", () => {
 
   describe("#getEntitySelection", () => {
     it("works", () => {
-      const contentBlocks = convertFromHTML("<h1>aaaaaaaaaa</h1>");
-      const contentState = ContentState.createFromBlockArray(contentBlocks);
-      let editorState = EditorState.createWithContent(contentState);
-      const updatedSelection = editorState.getSelection().merge({
+      const content = ContentState.createFromText("hello, world");
+      let editorState = EditorState.createWithContent(content);
+      const selection = editorState.getSelection().merge({
         anchorOffset: 0,
-        focusOffset: 5,
+        focusOffset: 4,
+      });
+
+      const contentStateWithEntity = content.createEntity("LINK", "MUTABLE", {
+        url: "www.testing.com",
       });
-      const contentStateWithEntity = contentState.createEntity(
-        "LINK",
-        "MUTABLE",
-        { url: "www.testing.com" },
-      );
       const entityKey = contentStateWithEntity.getLastCreatedEntityKey();
-      editorState = RichUtils.toggleLink(
+      editorState = RichUtils.toggleLink(editorState, selection, entityKey);
+      editorState = EditorState.forceSelection(
         editorState,
-        updatedSelection,
-        entityKey,
+        selection.merge({ focusOffset: 0 }),
       );
-      const entitySelection = DraftUtils.getEntitySelection(
+      expect(
+        DraftUtils.getEntitySelection(editorState, entityKey).toJS(),
+      ).toMatchObject({
+        anchorOffset: 0,
+        focusOffset: 4,
+      });
+    });
+
+    it("supports backwards selections (#168)", () => {
+      const content = ContentState.createFromText("hello, world");
+      let editorState = EditorState.createWithContent(content);
+      const selection = editorState.getSelection().merge({
+        anchorOffset: 5,
+        focusOffset: 0,
+        isBackward: true,
+      });
+      const contentStateWithEntity = content.createEntity("LINK", "MUTABLE", {
+        url: "www.testing.com",
+      });
+      const entityKey = contentStateWithEntity.getLastCreatedEntityKey();
+      editorState = RichUtils.toggleLink(editorState, selection, entityKey);
+      editorState = EditorState.forceSelection(
         editorState,
-        entityKey,
+        selection.merge({ anchorOffset: 0 }),
       );
-      expect(entitySelection.toJS()).toMatchObject({
-        anchorOffset: 0,
-        focusOffset: 5,
+      expect(
+        DraftUtils.getEntitySelection(editorState, entityKey).toJS(),
+      ).toMatchObject({
+        anchorOffset: 5,
+        focusOffset: 0,
+        isBackward: true,
       });
     });
+
+    it("entity not found should not change selection (#168)", () => {
+      const content = ContentState.createFromText("hello, world");
+      const editorState = EditorState.createWithContent(content);
+      expect(DraftUtils.getEntitySelection(editorState, "1")).toBe(
+        editorState.getSelection(),
+      );
+    });
+
+    it("missing entity key should not change selection (#168)", () => {
+      const content = ContentState.createFromText("hello, world");
+      const editorState = EditorState.createWithContent(content);
+      expect(DraftUtils.getEntitySelection(editorState, null)).toBe(
+        editorState.getSelection(),
+      );
+    });
   });
 
   describe("#updateBlockEntity", () => {