[download] add tests for AutoVerifyingInputStream

libs/download/src/androidUnitTest/kotlin/org/fdroid/download/glide/AutoVerifyingInputStreamTest.kt

@@ -0,0 +1,69 @@
+package org.fdroid.download.glide
+
+import java.io.ByteArrayInputStream
+import java.io.IOException
+import kotlin.test.Test
+import kotlin.test.assertContentEquals
+import kotlin.test.assertEquals
+import kotlin.test.assertFailsWith
+
+internal class AutoVerifyingInputStreamTest {
+
+    private val testBytes = """
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+        this is test data for the AutoVerifyingInputStream
+    """.trimIndent().toByteArray()
+    private val testHash = "784973023c9e3f32a750f3bc566bb13ee3f46b3811c2f269e2d11b47f07d1dab"
+
+    @Test
+    fun testSuccess() {
+        AutoVerifyingInputStream(
+            inputStream = ByteArrayInputStream(testBytes),
+            expectedHash = testHash,
+        ).use { inputStream ->
+            assertContentEquals(testBytes, inputStream.readBytes())
+        }
+    }
+
+    @Test
+    fun testHashMismatch() {
+        val e = assertFailsWith<IOException> {
+            AutoVerifyingInputStream(
+                inputStream = ByteArrayInputStream(testBytes),
+                expectedHash = "684973023c9e3f32a750f3bc566bb13ee3f46b3811c2f269e2d11b47f07d1dab",
+            ).use { inputStream ->
+                inputStream.readBytes()
+            }
+        }
+        assertEquals("Hash not matching.", e.message)
+    }
+
+    @Test
+    fun testMaxBytesToRead() {
+        val e = assertFailsWith<IOException> {
+            AutoVerifyingInputStream(
+                inputStream = ByteArrayInputStream(testBytes),
+                expectedHash = testHash,
+                maxBytesToRead = 42,
+            ).use { inputStream ->
+                inputStream.readBytes()
+            }
+        }
+        assertEquals("Read ${testBytes.size} bytes, above maximum allowed.", e.message)
+    }
+
+}