testing: add unit test framework

Add junit/espresso alongside a few basic tests.

I am nowhere near close to being "done" with this at all.

app/build.gradle

@@ -18,9 +18,7 @@ android {
         minSdk 21
         targetSdk 33
 
-        buildFeatures {
-            viewBinding true
-        }
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
 
     // ExoPlayer, AndroidX, and Material Components all need Java 8 to compile.
@@ -47,6 +45,10 @@ android {
         }
     }
 
+    buildFeatures {
+        viewBinding true
+    }
+
     dependenciesInfo {
         includeInApk = false
         includeInBundle = false
@@ -110,8 +112,11 @@ dependencies {
     // Locked below 1.7.0-alpha03 to avoid the same ripple bug
     implementation "com.google.android.material:material:1.7.0-alpha02"
 
-    // LeakCanary
+    // Development
     debugImplementation "com.squareup.leakcanary:leakcanary-android:2.9.1"
+    testImplementation "junit:junit:4.13.2"
+    androidTestImplementation 'androidx.test.ext:junit:1.1.4'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.0'
 }
 
 spotless {

app/src/androidTest/java/org/oxycblt/auxio/StubTest.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2023 Auxio Project
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.Assert.*
+import org.junit.runner.RunWith
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class StubTest {
+    // TODO: Add tests
+}

app/src/main/java/org/oxycblt/auxio/music/Date.kt

@@ -74,7 +74,7 @@ class Date private constructor(private val tokens: List<Int>) : Comparable<Date>
 
     override fun hashCode() = tokens.hashCode()
 
-    override fun equals(other: Any?) = other is Date && tokens == other.tokens
+    override fun equals(other: Any?) = other is Date && other.compareTo(this) == 0
 
     override fun compareTo(other: Date): Int {
         for (i in 0 until max(tokens.size, other.tokens.size)) {

app/src/test/java/org/oxycblt/auxio/music/DateTest.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2023 Auxio Project
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.music
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class DateTest {
+    // TODO: Incomplete
+
+    @Test
+    fun date_fromYear() {
+        assertEquals(Date.from(2016).toString(), "2016")
+    }
+
+    @Test
+    fun date_fromDate() {
+        assertEquals(Date.from(2016, 8, 16).toString(), "2016-08-16")
+    }
+
+    @Test
+    fun date_fromDatetime() {
+        assertEquals(Date.from(2016, 8, 16, 0, 1).toString(), "2016-08-16T00:01Z")
+    }
+
+    @Test
+    fun date_fromFormalTimestamp() {
+        assertEquals(Date.from("2016-08-16T00:01:02").toString(), "2016-08-16T00:01:02Z")
+    }
+
+    @Test
+    fun date_fromSpacedTimestamp() {
+        assertEquals(Date.from("2016-08-16 00:01:02").toString(), "2016-08-16T00:01:02Z")
+    }
+
+    @Test
+    fun date_fromDatestamp() {
+        assertEquals(Date.from("2016-08-16").toString(), "2016-08-16")
+    }
+
+    @Test
+    fun date_fromWeirdDateTimestamp() {
+        assertEquals(Date.from("2016-08-16T00:01").toString(), "2016-08-16T00:01Z")
+    }
+
+    @Test
+    fun date_fromWeirdDatestamp() {
+        assertEquals(Date.from("2016-08").toString(), "2016-08")
+    }
+
+    @Test
+    fun date_fromYearStamp() {
+        assertEquals(Date.from("2016").toString(), "2016")
+    }
+
+    @Test
+    fun date_fromWackTimestamp() {
+        assertEquals(Date.from("2016-11-32 25:43:01").toString(), "2016-11")
+    }
+
+    @Test
+    fun date_fromWackYear() {
+        assertEquals(Date.from(0), null)
+    }
+}

app/src/test/java/org/oxycblt/auxio/music/parsing/ParsingUtilTest.kt

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2023 Auxio Project
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+ 
+package org.oxycblt.auxio.music.parsing
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ParsingUtilTest {
+    @Test
+    fun splitEscaped_correct() {
+        assertEquals("a,b,c".splitEscaped { it == ',' }, listOf("a", "b", "c"))
+    }
+
+    @Test
+    fun splitEscaped_escaped() {
+        assertEquals("a\\,b,c".splitEscaped { it == ',' }, listOf("a,b", "c"))
+    }
+
+    @Test
+    fun splitEscaped_whitespace() {
+        assertEquals("a , b, c ,  ".splitEscaped { it == ',' }, listOf("a ", " b", " c ", "  "))
+    }
+
+    @Test
+    fun splitEscaped_escapedWhitespace() {
+        assertEquals("a \\, b, c ,  ".splitEscaped { it == ',' }, listOf("a , b", " c ", "  "))
+    }
+
+    @Test
+    fun correctWhitespace_stringCorrect() {
+        assertEquals(
+            " asymptotic self-improvement  ".correctWhitespace(), "asymptotic self-improvement")
+    }
+
+    @Test
+    fun correctWhitespace_stringOopsAllWhitespace() {
+        assertEquals("      ".correctWhitespace(), null)
+    }
+
+    @Test
+    fun correctWhitespace_listCorrect() {
+        assertEquals(
+            listOf(" asymptotic self-improvement  ", "  daemons never stop", "tcp phagocyte")
+                .correctWhitespace(),
+            listOf("asymptotic self-improvement", "daemons never stop", "tcp phagocyte"))
+    }
+
+    @Test
+    fun correctWhitespace_listOopsAllWhitespacE() {
+        assertEquals(
+            listOf("      ", "", "  tcp phagocyte").correctWhitespace(), listOf("tcp phagocyte"))
+    }
+
+    @Test
+    fun parseId3v2Position_correct() {
+        assertEquals("16/32".parseId3v2Position(), 16)
+    }
+
+    @Test
+    fun parseId3v2Position_noTotal() {
+        assertEquals("16".parseId3v2Position(), 16)
+    }
+
+    @Test
+    fun parseId3v2Position_wack() {
+        assertEquals("16/".parseId3v2Position(), 16)
+    }
+}