1 files changed, 47 insertions, 0 deletions
diff --git a/__tests__/string-utils.ts b/__tests__/string-utils.ts
new file mode 100644
index 000000000..9e0cd1c3e
--- /dev/null
+++ b/__tests__/string-utils.ts
@@ -0,0 +1,47 @@
+import {extractEntities} from '../src/view/lib/strings'
+
+describe('extractEntities', () => {
+  const inputs = [
+    'no mention',
+    '@start middle end',
+    'start @middle end',
+    'start middle @end',
+    '@start @middle @end',
+    '@full123.test-of-chars',
+    'not@right',
+    '@bad!@#$chars',
+    '@newline1\n@newline2',
+  ]
+  const outputs = [
+    undefined,
+    [{index: [0, 6], type: 'mention', value: 'start'}],
+    [{index: [6, 13], type: 'mention', value: 'middle'}],
+    [{index: [13, 17], type: 'mention', value: 'end'}],
+    [
+      {index: [0, 6], type: 'mention', value: 'start'},
+      {index: [7, 14], type: 'mention', value: 'middle'},
+      {index: [15, 19], type: 'mention', value: 'end'},
+    ],
+    [{index: [0, 22], type: 'mention', value: 'full123.test-of-chars'}],
+    undefined,
+    [{index: [0, 4], type: 'mention', value: 'bad'}],
+    [
+      {index: [0, 9], type: 'mention', value: 'newline1'},
+      {index: [10, 19], type: 'mention', value: 'newline2'},
+    ],
+  ]
+  it('correctly handles a set of text inputs', () => {
+    for (let i = 0; i < inputs.length; i++) {
+      const input = inputs[i]
+      const output = extractEntities(input)
+      expect(output).toEqual(outputs[i])
+      if (output) {
+        for (const outputItem of output) {
+          expect(input.slice(outputItem.index[0], outputItem.index[1])).toBe(
+            `@${outputItem.value}`,
+          )
+        }
+      }
+    }
+  })
+})