add tests to fromString

tests/cypress/integration/core/fromString.spec.ts

@@ -0,0 +1,41 @@
+/// <reference types="cypress" />
+
+import { fromString } from '@tiptap/core'
+
+describe('fromString', () => {
+  it('parse a string', () => {
+    const value = fromString('test')
+
+    expect(value).to.eq('test')
+  })
+
+  it('parse a number', () => {
+    const value = fromString('1')
+
+    expect(value).to.eq(1)
+  })
+
+  it('parse a floating number', () => {
+    const value = fromString('1.2')
+
+    expect(value).to.eq(1.2)
+  })
+
+  it('parse not a number with exponent', () => {
+    const value = fromString('1e1')
+
+    expect(value).to.eq('1e1')
+  })
+
+  it('parse a boolean (true)', () => {
+    const value = fromString('true')
+
+    expect(value).to.eq(true)
+  })
+
+  it('parse a boolean (false)', () => {
+    const value = fromString('false')
+
+    expect(value).to.eq(false)
+  })
+})