test: raise coverage

Signed-off-by: Jakub Freisler <[email protected]>

Author: FRSgit

src/constants.ts

@@ -1,3 +1,4 @@
+/* c8 ignore start */
 const PLUGIN_NAME = "cp-visual-regression-diff";
 export const LINK_PREFIX = `#${PLUGIN_NAME}-`;
 export const OVERLAY_CLASS = `${PLUGIN_NAME}-overlay`;
@@ -18,3 +19,4 @@ export const TASK = {
 };
 
 export const METADATA_KEY = "FRSOURCE_CPVRD_V";
+/* c8 ignore stop */

src/image.utils.ts

@@ -9,11 +9,13 @@ import { wasScreenshotUsed } from "./screenshotPath.utils";
 import { METADATA_KEY } from "./constants";
 
 export const addPNGMetadata = (png: Buffer) =>
-  addMetadata(png, METADATA_KEY, version);
-export const getPNGMetadata = (png: Buffer) => getMetadata(png, METADATA_KEY);
+  addMetadata(png, METADATA_KEY, version /* c8 ignore next */);
+export const getPNGMetadata = (png: Buffer) =>
+  getMetadata(png, METADATA_KEY /* c8 ignore next */);
 export const isImageCurrentVersion = (png: Buffer) =>
   getPNGMetadata(png) === version;
-export const isImageGeneratedByPlugin = (png: Buffer) => !!getPNGMetadata(png);
+export const isImageGeneratedByPlugin = (png: Buffer) =>
+  !!getPNGMetadata(png /* c8 ignore next */);
 
 export const writePNG = (name: string, png: PNG | Buffer) =>
   fs.writeFileSync(