EZQMS-398: Add StringDiffViewer (#4085)

Signed-off-by: Anna No <anna.no@xored.com>

packages/text-editor/src/components/StringDiffViewer.svelte

@@ -0,0 +1,36 @@
+<!--
+//
+// Copyright © 2022, 2023 Hardcore Engineering Inc.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+-->
+<script lang="ts">
+  import * as Diff from 'diff'
+
+  export let value: string
+  export let compareTo: string
+  export let method: 'diffChars' | 'diffWords' | 'diffWordsWithSpace' = 'diffChars'
+
+  const handleDiff = (oldValue: string, newValue: string) => Diff[method](oldValue, newValue)
+
+  $: changes = handleDiff(value, compareTo)
+</script>
+
+{#each changes as change}
+  <span
+    class:text-editor-highlighted-node-add={change.added}
+    class:text-editor-highlighted-node-delete={change.removed}
+  >
+    {change.value}
+  </span>
+{/each}

packages/text-editor/src/index.ts

@@ -23,6 +23,7 @@ export { default as CollaboratorEditor } from './components/CollaboratorEditor.s
 export { default as FullDescriptionBox } from './components/FullDescriptionBox.svelte'
 export { default as MarkupDiffViewer } from './components/MarkupDiffViewer.svelte'
 export { default as ReferenceInput } from './components/ReferenceInput.svelte'
+export { default as StringDiffViewer } from './components/StringDiffViewer.svelte'
 export { default as StyleButton } from './components/StyleButton.svelte'
 export { default as StyledTextArea } from './components/StyledTextArea.svelte'
 export { default as StyledTextBox } from './components/StyledTextBox.svelte'