Merge pull request #3424 from obsidian-tasks-group/fix-3342-on-completion-blank-line

fix: Stop onCompletion: delete leaving blank lines for non-recurring tasks

Author: claremacrae

resources/sample_vaults/Tasks-Demo/Manual Testing/Task Toggling Scenarios/On Completion Delete.md

@@ -13,7 +13,7 @@
 - [ ] #task Complete in **Source Mode** with `Tasks: Toggle task done` command 🏁 delete
 - Line after
 
-==❌ This shows \#3342 - blank line remains, as of Tasks `7.18.4`.==
+✅ Whole line is removed.
 
 ## Live Preview
 
@@ -23,15 +23,15 @@
 - [ ] #task Complete in **Live Preview** with `Tasks: Toggle task done` command 🏁 delete
 - Line after
 
-==❌ This shows \#3342 - blank line remains, as of Tasks `7.18.4`.==
+✅ Whole line is removed.
 
 ### Complete in Live Preview clicking checkbox
 
 - Line before
 - [ ] #task Complete in **Live Preview** clicking checkbox 🏁 delete
 - Line after
 
-==❌ This shows \#3342 - blank line remains, as of Tasks `7.18.4`.==
+✅ Whole line is removed.
 
 ## Reading Mode
 
@@ -43,6 +43,14 @@
 
 ✅ Whole line is removed.
 
+### Complete in Reading Mode right-clicking checkbox
+
+- Line before
+- [ ] #task Complete in **Reading Mode** right-clicking checkbox 🏁 delete
+- Line after
+
+✅ Whole line is removed.
+
 ## Search results
 
 ### Complete in Search results clicking checkbox
@@ -51,14 +59,24 @@
 - [ ] #task Complete in **Search result**s clicking checkbox 🏁 delete
 - Line after
 
+✅ Whole line is removed.
+
+### Complete in Search results right-clicking checkbox
+
+- Line before
+- [ ] #task Complete in **Search result**s right-clicking checkbox 🏁 delete
+- Line after
+
+✅ Whole line is removed.
+
+### Search
+
 ```tasks
 path includes {{query.file.path}}
-heading includes Complete in Search results clicking checkbox
+heading includes Complete in Search results
 short mode
 ```
 
-✅ Whole line is removed.
-
 ## Remaining steps
 
 ```tasks

src/Commands/ToggleDone.ts

@@ -36,7 +36,18 @@ export const toggleDone = (checking: boolean, editor: Editor, view: MarkdownView
     const line = editor.getLine(lineNumber);
 
     const insertion = toggleLine(line, path);
-    editor.setLine(lineNumber, insertion.text);
+
+    const replacementTextIsNonEmpty = insertion.text.length > 0;
+    const taskIsOnLastLine = lineNumber >= editor.lineCount() - 1;
+    if (replacementTextIsNonEmpty || taskIsOnLastLine) {
+        editor.setLine(lineNumber, insertion.text);
+    } else {
+        // The replacement text is empty, and our line was followed by a new line character,
+        // so we delete the line and the new-line, to avoid leaving a blank line in the file.
+        const from = { line: lineNumber, ch: 0 };
+        const to = { line: lineNumber + 1, ch: 0 };
+        editor.replaceRange('', from, to);
+    }
 
     /* Cursor positions are 0-based for both "line" and "ch" offsets.
      * If "ch" offset bigger than the line length, will just continue to next line(s).

src/Obsidian/LivePreviewExtension.ts

@@ -91,11 +91,22 @@ class LivePreviewExtension implements PluginValue {
         const toggled = task.toggleWithRecurrenceInUsersOrder();
         const toggledString = toggled.map((t) => t.toFileLineString()).join(state.lineBreak);
 
+        let to = line.to;
+
+        if (toggledString === '') {
+            // We also need to remove any line break at the end of the line.
+            const nextLine = line.number < state.doc.lines ? state.doc.line(line.number + 1) : null;
+            if (nextLine) {
+                // If not the last line, delete up to the start of the next line, including the line break
+                to = nextLine.from;
+            }
+        }
+
         // Creates a CodeMirror transaction in order to update the document.
         const transaction = state.update({
             changes: {
                 from: line.from,
-                to: line.to,
+                to,
                 insert: toggledString,
             },
         });