Fix to ignore non-permanent redirects

Related-to: GH-54.

lib/index.js

@@ -169,7 +169,11 @@ async function rule(tree, file, options) {
               product.fatal = message.fatal
             }
 
-            if (result.status === 'alive' && new URL(url).href !== result.url) {
+            if (
+              result.permanent &&
+              result.status === 'alive' &&
+              new URL(url).href !== result.url
+            ) {
               const message = file.message(
                 'Unexpected redirecting URL `' +
                   url +

test.js

@@ -327,7 +327,7 @@ No URLs in here.
     assert.deepEqual(file.messages.map(String), [])
   })
 
-  await t.test('should support redirects', async function () {
+  await t.test('should support permanent redirects', async function () {
     const globalDispatcher = getGlobalDispatcher()
     const mockAgent = new MockAgent()
     mockAgent.enableNetConnect(/(?=a)b/)
@@ -354,4 +354,30 @@ No URLs in here.
       '1:1-1:30: Unexpected redirecting URL `https://example.com/from`, expected final URL `https://example.com/to`'
     ])
   })
+
+  await t.test('should support temporary redirects', async function () {
+    const globalDispatcher = getGlobalDispatcher()
+    const mockAgent = new MockAgent()
+    mockAgent.enableNetConnect(/(?=a)b/)
+    setGlobalDispatcher(mockAgent)
+    const site = mockAgent.get('https://example.com')
+
+    site.intercept({path: '/from'}).reply(302, '', {
+      headers: {Location: '/to'}
+    })
+
+    site.intercept({path: '/to'}).reply(200, 'ok', {
+      headers: {'Content-Type': 'text/html'}
+    })
+
+    const document = `[a](https://example.com/from)`
+    const file = await remark().use(remarkLintNoDeadUrls).process(document)
+
+    await mockAgent.close()
+    await setGlobalDispatcher(globalDispatcher)
+
+    file.messages.sort(compareMessage)
+
+    assert.deepEqual(file.messages.map(String), [])
+  })
 })