1 files changed, 67 insertions, 0 deletions
diff --git a/app/src/test/java/org/terst/feedreader/data/CachedExtractionTest.kt b/app/src/test/java/org/terst/feedreader/data/CachedExtractionTest.kt
new file mode 100644
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+++ b/app/src/test/java/org/terst/feedreader/data/CachedExtractionTest.kt
@@ -0,0 +1,67 @@
+package org.terst.feedreader.data
+
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * The reported bug came with "extractedContent cached: true", which is the half
+ * that a fixed extractor cannot reach: the cookie disclaimer was already written
+ * to `articles.extractedContent`, and every open after that read it straight back
+ * out without ever looking at it again.
+ *
+ * So a poisoned cache has to be recognised and dropped on read, not just kept out
+ * on write.
+ */
+class CachedExtractionTest {
+
+    private val cookieNotice =
+        "<div id=\"readability-page-1\" class=\"page\"><div id=\"didomi-host\"><p>This website uses " +
+            "cookies and other tracking technologies (“Cookies”) to enhance user experience, to " +
+            "display targeted ads, and to analyze performance and user activity on our website. For " +
+            "more information about our use of Cookies and our privacy practices, see our Privacy " +
+            "Policy. By continuing to use this website, you agree to our Terms and Conditions.</p>" +
+            "</div></div>"
+
+    @Test
+    fun `real cached content is used as-is and the cache is left alone`() = runTest {
+        var cleared = false
+        val content = "<p>" + "The actual article body. ".repeat(60) + "</p>"
+        val result = loadCachedExtraction(content) { cleared = true }
+        assertEquals(content, result.content)
+        assertFalse(result.discardedConsentNotice)
+        assertFalse("a good cache must not be cleared", cleared)
+    }
+
+    @Test
+    fun `a cached consent notice is discarded and deleted`() = runTest {
+        var cleared = false
+        val result = loadCachedExtraction(cookieNotice) { cleared = true }
+        assertNull("the notice must not be shown as the article", result.content)
+        assertTrue(result.discardedConsentNotice)
+        assertTrue("the poisoned row must be cleared so a re-extract can replace it", cleared)
+    }
+
+    @Test
+    fun `nothing cached touches nothing`() = runTest {
+        var cleared = false
+        val result = loadCachedExtraction(null) { cleared = true }
+        assertNull(result.content)
+        assertFalse(result.discardedConsentNotice)
+        assertFalse(cleared)
+    }
+
+    // A blank value is as good as nothing cached -- it is not a consent notice, so
+    // reporting it as a discarded one would make the caller re-extract on a false
+    // premise.
+    @Test
+    fun `a blank cached value is not reported as a discarded notice`() = runTest {
+        var cleared = false
+        val result = loadCachedExtraction("   ") { cleared = true }
+        assertFalse(result.discardedConsentNotice)
+        assertFalse(cleared)
+    }
+}