✅ Add JUnit Rule to override locales during tests

Some tests fail when run with a non-English locale. This was found by debbiedub (see https://github.com/Bombe/Sone/pull/23) but their proposed solution was not quite to my liking.

This TestRule will store the JVM’s current default locale and set a custom locale before running a test. After the test the previous locale will be restored, in order not to mess up any other tests.

diff --git a/src/test/kotlin/net/pterodactylus/sone/test/OverrideLocale.kt b/src/test/kotlin/net/pterodactylus/sone/test/OverrideLocale.kt
new file mode 100644 (file)
index 0000000..c4b4b0d
--- /dev/null
+++ b/src/test/kotlin/net/pterodactylus/sone/test/OverrideLocale.kt
@@ -0,0 +1,24 @@
+package net.pterodactylus.sone.test
+
+import org.junit.rules.ExternalResource
+import java.util.Locale
+
+/**
+ * JUnit [test rule][org.junit.rules.TestRule] that overrides the
+ * [JVM’s default locale][Locale.getDefault] for the duration of a test,
+ * restoring it to its previous value after the test.
+ */
+class OverrideLocale(private val locale: Locale) : ExternalResource() {
+
+       override fun before() {
+               previousLocale = Locale.getDefault()
+               Locale.setDefault(locale)
+       }
+
+       override fun after() {
+               Locale.setDefault(previousLocale)
+       }
+
+       private var previousLocale: Locale? = null
+
+}