1 files changed, 75 insertions, 0 deletions
diff --git a/app/assets/javascripts/diffs/utils/diff_file.js b/app/assets/javascripts/diffs/utils/diff_file.js
new file mode 100644
index 00000000000..69d0e49e501
--- /dev/null
+++ b/app/assets/javascripts/diffs/utils/diff_file.js
@@ -0,0 +1,75 @@
+import {
+  DIFF_FILE_SYMLINK_MODE,
+  DIFF_FILE_DELETED_MODE,
+  DIFF_FILE_MANUAL_COLLAPSE,
+  DIFF_FILE_AUTOMATIC_COLLAPSE,
+} from '../constants';
+import { uuids } from './uuids';
+
+function fileSymlinkInformation(file, fileList) {
+  const duplicates = fileList.filter(iteratedFile => iteratedFile.file_hash === file.file_hash);
+  const includesSymlink = duplicates.some(iteratedFile => {
+    return [iteratedFile.a_mode, iteratedFile.b_mode].includes(DIFF_FILE_SYMLINK_MODE);
+  });
+  const brokenSymlinkScenario = duplicates.length > 1 && includesSymlink;
+
+  return (
+    brokenSymlinkScenario && {
+      replaced: file.b_mode === DIFF_FILE_DELETED_MODE,
+      wasSymbolic: file.a_mode === DIFF_FILE_SYMLINK_MODE,
+      isSymbolic: file.b_mode === DIFF_FILE_SYMLINK_MODE,
+      wasReal: ![DIFF_FILE_SYMLINK_MODE, DIFF_FILE_DELETED_MODE].includes(file.a_mode),
+      isReal: ![DIFF_FILE_SYMLINK_MODE, DIFF_FILE_DELETED_MODE].includes(file.b_mode),
+    }
+  );
+}
+
+function collapsed(file) {
+  const viewer = file.viewer || {};
+
+  return {
+    automaticallyCollapsed: viewer.automaticallyCollapsed || viewer.collapsed || false,
+    manuallyCollapsed: null,
+  };
+}
+
+function identifier(file) {
+  return uuids({
+    seeds: [file.file_identifier_hash, file.blob?.id],
+  })[0];
+}
+
+export function prepareRawDiffFile({ file, allFiles, meta = false }) {
+  const additionalProperties = {
+    brokenSymlink: fileSymlinkInformation(file, allFiles),
+    viewer: {
+      ...file.viewer,
+      ...collapsed(file),
+    },
+  };
+
+  // It's possible, but not confirmed, that `content_sha` isn't available sometimes
+  // See: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/49506#note_464692057
+  // We don't want duplicate IDs if that's the case, so we just don't assign an ID
+  if (!meta && file.blob?.id) {
+    additionalProperties.id = identifier(file);
+  }
+
+  return Object.assign(file, additionalProperties);
+}
+
+export function collapsedType(file) {
+  const isManual = typeof file.viewer?.manuallyCollapsed === 'boolean';
+
+  return isManual ? DIFF_FILE_MANUAL_COLLAPSE : DIFF_FILE_AUTOMATIC_COLLAPSE;
+}
+
+export function isCollapsed(file) {
+  const type = collapsedType(file);
+  const collapsedStates = {
+    [DIFF_FILE_AUTOMATIC_COLLAPSE]: file.viewer?.automaticallyCollapsed || false,
+    [DIFF_FILE_MANUAL_COLLAPSE]: file.viewer?.manuallyCollapsed,
+  };
+
+  return collapsedStates[type];
+}