fix(jest): handle when jest-diff default import is object

ext · ext · commit 74f9b8424e0b · 2021-09-19T01:03:04.000+02:00
diff --git a/src/matchers.ts b/src/matchers.ts
@@ -13,9 +13,23 @@ interface TokenMatcher {
 	data?: any;
 }
 
+/* ignore typing for compatibility so it will seem "impossible" but different version will yield different source */
+const diffCandidates: Array<typeof jestDiff.diff> = [
+	// @ts-ignore
+	jestDiffDefault?.diff,
+	// @ts-ignore
+	jestDiffDefault,
+	// @ts-ignore
+	jestDiff?.diff,
+	// @ts-ignore
+	jestDiff,
+];
+
+const isFunction = (fn: unknown): boolean => typeof fn === "function";
+
 /* istanbul ignore next: covered by compatibility tests but not a single pass */
-/* @ts-ignore typing for compatibility so it will seem "impossible" but different version will yield different source */
-const diff: typeof jestDiff.diff = jestDiffDefault ?? jestDiff?.diff ?? jestDiff;
+/* @ts-ignore assume one of the candidate matches, there will be a reasonable error later on if not */
+const diff: typeof jestDiff.diff = diffCandidates.find(isFunction);
 
 declare global {
 	namespace jest {
