Add support for the cache-hit output

action.yml

@@ -11,6 +11,9 @@ inputs:
   working-directory:
     description: "The working directory this action should operate in"
     required: false
+outputs:
+  cache-hit:
+    description: 'A boolean value that indicates an exact match was found'
 runs:
   using: "node12"
   main: "dist/restore/index.js"

src/restore.ts

@@ -22,12 +22,22 @@ async function run() {
 
         await cleanTarget(packages);
       }
+
+      setCacheHitOutput(restoreKey === key);
     } else {
       core.info("No cache found.");
+
+      setCacheHitOutput(false);
     }
   } catch (e) {
+    setCacheHitOutput(false);
+
     core.info(`[warning] ${e.message}`);
   }
 }
 
+function setCacheHitOutput(cacheHit: boolean): void {
+  core.setOutput("cache-hit", cacheHit.toString());
+}
+
 run();