Add delete text action #15

yibolu · 2020-08-25T05:37:21Z

Added delete text action and its test.
The delete text action will be used by the BACKSPACE handler, which will delete a single char if a single place gets selected, and will delete a chunk of text if they are selected.

Currently, delete action has two modes:

delete single char
delete multiple chars among either multiple segments/single segment.

Only #1 will be used currently since we don't have the handlers for mouse up/down, and selection service either.

magicoder10 · 2020-08-30T23:39:57Z

src/common/array.ts

 export function insert<T>(arr: T[], index: number, slice: T[]): T[] {
    return [...arr.slice(0, index), ...slice, ...arr.slice(index)];
 }
+
+export function remove<T>(arr: T[], idx: number, count: number = 1): T[] {
+    return [
+        ...arr.slice(0, idx),
+        ...arr.slice(idx + count)
+    ];
+}


We are going to use those helpers over & over again. Let's include unit tests for them so that we are confident they are working correctly when dealing with complexities for the actions.

magicoder10 · 2020-08-30T23:47:08Z

src/state/delete-text.action.test.ts

+            }
+        },
+        {
+            name: 'should delete 1 character at cursor position and should delete the segment when segment is empty',


Suggested change

name: 'should delete 1 character at cursor position and should delete the segment when segment is empty',

name: 'should delete 1 character and the empty segment',

magicoder10 · 2020-08-30T23:48:49Z

src/state/delete-text.action.test.ts

+            }
+        },
+        {
+            name: 'should delete multiple characters at cursor selection',


Suggested change

name: 'should delete multiple characters at cursor selection',

name: 'should delete all selected characters in a single segment',

magicoder10 · 2020-08-30T23:49:53Z

src/state/delete-text.action.test.ts

+
+    const testCases: ITestCase[] = [
+        {
+            name: 'should delete 1 character at cursor position',


Suggested change

name: 'should delete 1 character at cursor position',

name: 'should delete 1 character in a single segment',

magicoder10 · 2020-08-30T23:51:00Z

src/state/delete-text.action.test.ts

+            }
+        },
+        {
+            name: 'should delete multiple characters at cursor selection among different start/end segment',


Suggested change

name: 'should delete multiple characters at cursor selection among different start/end segment',

name: 'should delete multiple selected characters across 2 segments',

magicoder10 · 2020-08-31T00:23:14Z