add match

src/index.ts

@@ -191,6 +191,12 @@ export class IntegrityMetadataSet {
     return [...new Set(strongestHashAlgorithms)];
   }
 
+  match(integrity: IntegrityMetadataLike | string | null | undefined): boolean {
+    return this.#set.some((integrityMetadata) =>
+      integrityMetadata.match(integrity),
+    );
+  }
+
   join(separator = " "): string {
     return this.#set.map(String).join(separator);
   }

test/integrity-metadata-set/match.js

@@ -0,0 +1,102 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { IntegrityMetadataSet } from "../../dist/index.js";
+
+test("if the hash values match, return true", function () {
+  const integrityMetadata = new IntegrityMetadataSet(
+    "sha256-MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+  );
+
+  assert.strictEqual(
+    integrityMetadata.match({
+      alg: "sha256",
+      val: "MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+    }),
+    true,
+  );
+});
+
+test("if the hash of one of the selected algorithms matches, return true", function () {
+  const integrityMetadata = new IntegrityMetadataSet([
+    "sha256-MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+    "sha256-uU0nuZNNPgilLlLX2n2r+sSE7+N6U4DukIj3rOLvzek=",
+  ]);
+
+  assert.strictEqual(
+    integrityMetadata.match({
+      alg: "sha256",
+      val: "MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+    }),
+    true,
+  );
+});
+
+test("a string can be specified", function () {
+  const integrityMetadata = new IntegrityMetadataSet(
+    "sha256-MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+  );
+
+  assert.strictEqual(
+    integrityMetadata.match(
+      "sha256-MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+    ),
+    true,
+  );
+});
+
+test("if the hash algorithms are different, return false", function () {
+  const integrityMetadata = new IntegrityMetadataSet(
+    "sha256-MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+  );
+
+  assert.strictEqual(
+    integrityMetadata.match({
+      alg: "sha512",
+      val: "MJ7MSJwS1utMxA9QyQLytNDtd+5RGnx6m808qG1M2G+YndNbxf9JlnDaNCVbRbDP2DDoH2Bdz33FVC6TrpzXbw==",
+    }),
+    false,
+  );
+});
+
+test("if the hash values are different, return false", function () {
+  const integrityMetadata = new IntegrityMetadataSet(
+    "sha256-MV9b23bQeMQ7isAGTkoBZGErH853yGk0W/yUx1iU7dM=",
+  );
+
+  assert.strictEqual(
+    integrityMetadata.match({
+      alg: "sha256",
+      val: "uU0nuZNNPgilLlLX2n2r+sSE7+N6U4DukIj3rOLvzek=",
+    }),
+    false,
+  );
+});
+
+test("if the hash algorithm is unsupported, return false", function () {
+  const integrityMetadata = new IntegrityMetadataSet(
+    "sha1-lDpwLQbzRZmu4fjajvn3KWAx1pk=",
+  );
+
+  assert.strictEqual(
+    integrityMetadata.match("sha1-lDpwLQbzRZmu4fjajvn3KWAx1pk="),
+    false,
+  );
+});
+
+test("if null, return false", function () {
+  const integrityMetadata = new IntegrityMetadataSet(null);
+
+  assert.strictEqual(integrityMetadata.match(null), false);
+});
+
+test("if empty, return false", function () {
+  const integrityMetadata = new IntegrityMetadataSet([]);
+
+  assert.strictEqual(integrityMetadata.match(""), false);
+});
+
+test("if invalid value, return false", function () {
+  const integrityMetadata = new IntegrityMetadataSet("md5\0/..invalid-value");
+
+  assert.strictEqual(integrityMetadata.match("md5\0/..invalid-value"), false);
+});