Merge pull request #3181 from vitorpamplona/claude/focused-knuth-4zi90p

Fix ThumbnailDiskCache to recreate cache dir if cleared at runtime

amethyst/src/androidTest/java/com/vitorpamplona/amethyst/service/images/ThumbnailDiskCacheInstrumentedTest.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.service.images
+
+import android.graphics.Bitmap
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import org.junit.After
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertTrue
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import java.io.File
+import java.util.UUID
+
+@RunWith(AndroidJUnit4::class)
+class ThumbnailDiskCacheInstrumentedTest {
+    private val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+    private lateinit var cacheDir: File
+    private lateinit var cache: ThumbnailDiskCache
+    private lateinit var sourceFile: File
+
+    @Before
+    fun setUp() {
+        cacheDir = File(appContext.cacheDir, "thumbnail-test-${UUID.randomUUID()}")
+        cache = ThumbnailDiskCache(cacheDir)
+        sourceFile = File(appContext.cacheDir, "source-${UUID.randomUUID()}.jpg")
+        val bitmap = Bitmap.createBitmap(64, 64, Bitmap.Config.ARGB_8888)
+        sourceFile.outputStream().use { bitmap.compress(Bitmap.CompressFormat.JPEG, 90, it) }
+        bitmap.recycle()
+    }
+
+    @After
+    fun tearDown() {
+        cacheDir.deleteRecursively()
+        sourceFile.delete()
+    }
+
+    @Test
+    fun generatesThumbnailFromJpeg() {
+        val url = "https://example.com/profile-pic-${UUID.randomUUID()}.jpg"
+
+        assertTrue("generateFromFile must return true for a valid JPEG", cache.generateFromFile(url, sourceFile))
+        assertNotNull("load() must return a non-null Bitmap for a cached JPEG", cache.load(url))
+    }
+
+    @Test
+    fun recreatesCacheDirClearedAtRuntime() {
+        // The system (cache trim) or the user (Settings > Clear cache) can delete
+        // the cache dir while the app runs; the next write must recreate it
+        // instead of failing with ENOENT.
+        val url = "https://example.com/profile-pic-${UUID.randomUUID()}.jpg"
+        assertTrue(cacheDir.deleteRecursively())
+
+        assertTrue(
+            "generateFromFile must recreate the cache dir after it is cleared at runtime",
+            cache.generateFromFile(url, sourceFile),
+        )
+        assertNotNull("load() must return the thumbnail written after dir recreation", cache.load(url))
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/service/images/ThumbnailDiskCache.kt

@@ -146,6 +146,9 @@ class ThumbnailDiskCache(
                 }
 
             val tempFile = File(cacheDir, "$key.tmp")
+            // The cache dir can be wiped while the app runs (system cache trim,
+            // user "Clear cache"); recreate it or the write fails with ENOENT.
+            cacheDir.mkdirs()
             tempFile.outputStream().use { out ->
                 scaled.compress(Bitmap.CompressFormat.JPEG, JPEG_QUALITY, out)
             }