diceware: add WordListParser and tests

passgen/diceware/src/main/kotlin/dev/msfjarvis/aps/passgen/diceware/WordListParser.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.passgen.diceware
+
+import java.io.InputStream
+
+internal object WordListParser {
+  fun parse(wordlistStream: InputStream) =
+    wordlistStream
+      .bufferedReader()
+      .lineSequence()
+      .map { line -> line.split(DELIMITER) }
+      .filter { items -> items.size == 2 && items[0].toIntOrNull() != null }
+      .map { items -> items[0].toInt() to items[1] }
+      .toMap()
+
+  private const val DELIMITER = "\t"
+}

passgen/diceware/src/test/kotlin/dev/msfjarvis/aps/passgen/diceware/WordListParserTest.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.passgen.diceware
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class WordListParserTest {
+  @Test
+  fun parseWordList() {
+    val stream = "11111\tabcde\n22222\tfghij".byteInputStream()
+    val parsedMap = WordListParser.parse(stream)
+    assertEquals(2, parsedMap.size)
+    assertEquals("abcde", parsedMap[11111])
+    assertEquals("fghij", parsedMap[22222])
+  }
+}