fix: Backspace in empty block deletes previous block (#1505)

* fix: removes current block instead of prev block if current block is empty

* Made code more descriptive + small fixes

---------

Co-authored-by: Matthew Lipski <[email protected]>

Author: Martinrsts

Diff for: packages/core/src/extensions/KeyboardShortcuts/KeyboardShortcutsExtension.ts

@@ -260,6 +260,73 @@ export const KeyboardShortcutsExtension = Extension.create<{
 
             return true;
           }),
+        // Deletes the current block if it's an empty block with inline content,
+        // and moves the selection to the previous block.
+        () =>
+          commands.command(({ state }) => {
+            const blockInfo = getBlockInfoFromSelection(state);
+            if (!blockInfo.isBlockContainer) {
+              return false;
+            }
+
+            const blockEmpty =
+              blockInfo.blockContent.node.childCount === 0 &&
+              blockInfo.blockContent.node.type.spec.content === "inline*";
+
+            if (blockEmpty) {
+              const prevBlockInfo = getPrevBlockInfo(
+                state.doc,
+                blockInfo.bnBlock.beforePos
+              );
+              if (!prevBlockInfo || !prevBlockInfo.isBlockContainer) {
+                return false;
+              }
+
+              let chainedCommands = chain();
+
+              if (
+                prevBlockInfo.blockContent.node.type.spec.content ===
+                "tableRow+"
+              ) {
+                const tableBlockEndPos = blockInfo.bnBlock.beforePos - 1;
+                const tableBlockContentEndPos = tableBlockEndPos - 1;
+                const lastRowEndPos = tableBlockContentEndPos - 1;
+                const lastCellEndPos = lastRowEndPos - 1;
+                const lastCellParagraphEndPos = lastCellEndPos - 1;
+
+                chainedCommands = chainedCommands.setTextSelection(
+                  lastCellParagraphEndPos
+                );
+              } else if (
+                prevBlockInfo.blockContent.node.type.spec.content === ""
+              ) {
+                const nonEditableBlockContentStartPos =
+                  prevBlockInfo.blockContent.afterPos -
+                  prevBlockInfo.blockContent.node.nodeSize;
+
+                chainedCommands = chainedCommands.setNodeSelection(
+                  nonEditableBlockContentStartPos
+                );
+              } else {
+                const blockContentStartPos =
+                  prevBlockInfo.blockContent.afterPos -
+                  prevBlockInfo.blockContent.node.nodeSize;
+
+                chainedCommands =
+                  chainedCommands.setTextSelection(blockContentStartPos);
+              }
+
+              return chainedCommands
+                .deleteRange({
+                  from: blockInfo.bnBlock.beforePos,
+                  to: blockInfo.bnBlock.afterPos,
+                })
+                .scrollIntoView()
+                .run();
+            }
+
+            return false;
+          }),
         // Deletes previous block if it contains no content and isn't a table,
         // when the selection is empty and at the start of the block. Moves the
         // current block into the deleted block's place.