Merge pull request #32135 from overleaf/mg-comment-empty-select

Allow adding comments on empty selection

GitOrigin-RevId: 14e742bb563fab99624be860691f1a9d2dabc00e

services/web/test/frontend/features/source-editor/utils/is-cursor-on-empty-line.test.ts

@@ -0,0 +1,44 @@
+import { expect } from 'chai'
+import { EditorState, EditorSelection } from '@codemirror/state'
+import { isCursorOnEmptyLine } from '../../../../../frontend/js/features/source-editor/utils/is-cursor-on-empty-line'
+
+function cursorState(doc: string, cursorPos: number) {
+  return EditorState.create({
+    doc,
+    selection: EditorSelection.cursor(cursorPos),
+  })
+}
+
+function selectionState(doc: string, from: number, to: number) {
+  return EditorState.create({
+    doc,
+    selection: EditorSelection.range(from, to),
+  })
+}
+
+describe('isCursorOnEmptyLine', function () {
+  it('returns true when cursor is on an empty line', function () {
+    const state = cursorState('hello\n\nworld', 6)
+    expect(isCursorOnEmptyLine(state)).to.be.true
+  })
+
+  it('returns true when cursor is on a whitespace-only line', function () {
+    const state = cursorState('hello\n   \nworld', 8)
+    expect(isCursorOnEmptyLine(state)).to.be.true
+  })
+
+  it('returns false when cursor is on a line with content', function () {
+    const state = cursorState('hello world', 3)
+    expect(isCursorOnEmptyLine(state)).to.be.false
+  })
+
+  it('returns false when there is an active selection', function () {
+    const state = selectionState('hello\n\nworld', 0, 5)
+    expect(isCursorOnEmptyLine(state)).to.be.false
+  })
+
+  it('returns false when selection spans an empty line', function () {
+    const state = selectionState('hello\n\nworld', 4, 8)
+    expect(isCursorOnEmptyLine(state)).to.be.false
+  })
+})

services/web/test/frontend/features/source-editor/utils/select-highlighted-or-nearest-token.test.ts

@@ -0,0 +1,81 @@
+import { expect } from 'chai'
+import { EditorState, EditorSelection } from '@codemirror/state'
+import { selectHighlightedOrNearestToken } from '../../../../../frontend/js/features/source-editor/utils/select-highlighted-or-nearest-token'
+
+function cursorState(doc: string, cursorPos: number) {
+  return EditorState.create({
+    doc,
+    selection: EditorSelection.cursor(cursorPos),
+  })
+}
+
+function selectionState(doc: string, from: number, to: number) {
+  return EditorState.create({
+    doc,
+    selection: EditorSelection.range(from, to),
+  })
+}
+
+function sliceRange(state: EditorState, range: { from: number; to: number }) {
+  return state.doc.sliceString(range.from, range.to)
+}
+
+describe('selectHighlightedOrNearestToken', function () {
+  it('returns current highlighted selection when it exists', function () {
+    const state = selectionState('hello world', 0, 5)
+    const result = selectHighlightedOrNearestToken(state)
+
+    expect(result).to.not.be.null
+    expect(sliceRange(state, result!)).to.equal('hello')
+  })
+
+  it('selects the token containing the cursor', function () {
+    const state = cursorState('hello world', 8)
+    const result = selectHighlightedOrNearestToken(state)
+
+    expect(result).to.not.be.null
+    expect(sliceRange(state, result!)).to.equal('world')
+  })
+
+  it('selects nearest token when cursor is in leading whitespace', function () {
+    const state = cursorState('   hello world', 0)
+    const result = selectHighlightedOrNearestToken(state)
+
+    expect(result).to.not.be.null
+    expect(sliceRange(state, result!)).to.equal('hello')
+  })
+
+  it('selects token when cursor is at its boundary', function () {
+    // pos 5 is immediately after "hello" (from=0, to=5) — pos equals to, so dist is 0
+    const state = cursorState('hello world', 5)
+    const result = selectHighlightedOrNearestToken(state)
+
+    expect(result).to.not.be.null
+    expect(sliceRange(state, result!)).to.equal('hello')
+  })
+
+  it('selects nearer token when cursor is between two tokens', function () {
+    // "hello   world" — pos 6, "hello" ends at 5 (dist 1), "world" starts at 8 (dist 2)
+    const state = cursorState('hello   world', 6)
+    const result = selectHighlightedOrNearestToken(state)
+
+    expect(result).to.not.be.null
+    expect(sliceRange(state, result!)).to.equal('hello')
+  })
+
+  it('selects earlier token when equidistant between two tokens', function () {
+    // "hello  world" — pos 6 is equidistant from "hello" (ends at 5, dist 1) and "world" (starts at 7, dist 1)
+    const state = cursorState('hello  world', 6)
+    const result = selectHighlightedOrNearestToken(state)
+
+    expect(result).to.not.be.null
+    expect(sliceRange(state, result!)).to.equal('hello')
+  })
+
+  it('returns null when line has no tokens', function () {
+    const state = cursorState('   \n\t  ', 2)
+    const result = selectHighlightedOrNearestToken(state)
+
+    expect(result).to.be.null
+  })
+})