Add tests for StringUtils

library/src/commonTest/kotlin/com/lagradost/cloudstream3/utils/StringUtilsTest.kt

@@ -0,0 +1,301 @@
+package com.lagradost.cloudstream3.utils
+
+import com.lagradost.cloudstream3.utils.StringUtils.decodeUrl
+import com.lagradost.cloudstream3.utils.StringUtils.encodeUrl
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+/**
+ * We test numerous edge cases here as well because some URLs
+ * are weird actually using things like control chars,
+ * or emojis in them.
+ */
+class StringUtilsTest {
+
+    @Test
+    fun encodeUrlPlainAsciiIsUnchanged() {
+        assertEquals("hello", "hello".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlEmptyStringStaysEmpty() {
+        assertEquals("", "".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlSingleSpaceBecomesPercent20() {
+        assertEquals("%20", " ".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlMultipleSpacesAreAllEncoded() {
+        assertEquals("%20%20%20", "   ".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlAmpersandIsEncoded() {
+        assertEquals("foo%26bar", "foo&bar".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlEqualsSignIsEncoded() {
+        assertEquals("key%3Dvalue", "key=value".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlPlusSignIsEncoded() {
+        assertEquals("a%2Bb", "a+b".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlHashIsEncoded() {
+        assertEquals("%23anchor", "#anchor".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlQuestionMarkIsEncoded() {
+        assertEquals("what%3Fever", "what?ever".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlSlashIsEncoded() {
+        assertEquals("path%2Fto%2Ffile", "path/to/file".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlPercentSignItselfIsEncoded() {
+        assertEquals("100%25", "100%".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlAlreadyPercentEncodedSequenceIsReEncoded() {
+        // "%20" should become "%2520" because % = %25
+        assertEquals("%2520", "%20".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlNonAsciiLatinCharactersAreEncoded() {
+        assertEquals("caf%C3%A9", "café".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlCjkCharactersAreEncoded() {
+        assertEquals("%E6%97%A5%E6%9C%AC%E8%AA%9E", "日本語".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlEmojiIsEncoded() {
+        assertEquals("%F0%9F%98%80", "\uD83D\uDE00".encodeUrl()) // 😀
+    }
+
+    @Test
+    fun encodeUrlFullUrlLikeStringEncodesReservedChars() {
+        assertEquals(
+            "https%3A%2F%2Fexample.com%2Fpath%3Fq%3Dhello%20world%26lang%3Den",
+            "https://example.com/path?q=hello world&lang=en".encodeUrl()
+        )
+    }
+
+    @Test
+    fun encodeUrlUnreservedCharsAreNotEncoded() {
+        // Per https://datatracker.ietf.org/doc/html/rfc3986#section-2.3
+        val unreserved = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.~"
+        assertEquals(unreserved, unreserved.encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlTabCharacterIsEncoded() {
+        assertEquals("a%09b", "a\tb".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlNewlineCharacterIsEncoded() {
+        assertEquals("a%0Ab", "a\nb".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlCarriageReturnIsEncoded() {
+        assertEquals("a%0Db", "a\rb".encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlLongStringDoesNotThrow() {
+        assertEquals("a".repeat(10_000), "a".repeat(10_000).encodeUrl())
+    }
+
+    @Test
+    fun encodeUrlCommonSpecialCharsAreEncoded() {
+        assertEquals(
+            "%21%40%23%24%25%5E%26%2A%28%29-_%3D%2B%5B%5D%7B%7D%7C%3B%3A%27%2C.%3C%3E%3F%2F%60~%5C%20%22",
+            "!@#\$%^&*()-_=+[]{}|;:',.<>?/`~\\ \"".encodeUrl()
+        )
+    }
+
+    @Test
+    fun encodeUrlEmojiSurrogatePairRoundTripsCleanly() {
+        val emoji = "😊"
+        assertEquals(emoji, emoji.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPlainStringIsUnchanged() {
+        assertEquals("hello", "hello".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlEmptyStringStaysEmpty() {
+        assertEquals("", "".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPercent20BecomesSpace() {
+        assertEquals(" ", "%20".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPlusSignStaysAsPlus() {
+        // This might unexpectedly differ some day.
+        assertEquals("+", "+".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPercent2BBecomesLiteralPlus() {
+        assertEquals("+", "%2B".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPercent26BecomesAmpersand() {
+        assertEquals("&", "%26".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPercent3DBecomesEquals() {
+        assertEquals("=", "%3D".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPercent23BecomesHash() {
+        assertEquals("#", "%23".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPercent25BecomesPercent() {
+        assertEquals("%", "%25".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlPercent2FBecomesSlash() {
+        assertEquals("/", "%2F".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlLowercaseHexWorks() {
+        assertEquals(" ", "%20".decodeUrl())
+        assertEquals("/", "%2f".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlMultiByteUtf8SequenceDecodesCorrectly() {
+        // é in UTF-8 is %C3%A9
+        assertEquals("é", "%C3%A9".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlCjkEncodedSequenceDecodesToOriginal() {
+        // 日 in UTF-8 is %E6%97%A5
+        assertEquals("日", "%E6%97%A5".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlEmojiEncodedSequenceDecodesToOriginal() {
+        // 😀 in UTF-8 is %F0%9F%98%80
+        assertEquals("😀", "%F0%9F%98%80".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlMixedEncodedAndPlainText() {
+        assertEquals("hello world&more", "hello%20world%26more".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlMultiplePlusSignsStayAsPlus() {
+        assertEquals("a+b+c", "a+b+c".decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlLongEncodedStringDoesNotThrow() {
+        assertEquals(" ".repeat(3_000), "%20".repeat(3_000).decodeUrl())
+    }
+
+    @Test
+    fun decodeUrlConsecutiveEncodedChars() {
+        assertEquals("&&", "%26%26".decodeUrl())
+    }
+
+    @Test
+    fun roundTripPlainAscii() {
+        val original = "hello world"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripEmptyString() {
+        assertEquals("", "".encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripAllCommonSpecialChars() {
+        val original = "!@#\$%^&*()-_=+[]{}|;:',.<>?/`~\\ \""
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripUrlLikeString() {
+        val original = "https://example.com/search?q=hello world&lang=en#section"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripLatinExtendedCharacters() {
+        val original = "àáâãäåæçèéêëìíîïðñòóôõöøùúûüýþÿ"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripCjkCharacters() {
+        val original = "日本語テスト"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripArabicCharacters() {
+        val original = "مرحبا بالعالم"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripEmoji() {
+        val original = "😀🎉🔥💯"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripNewlinesAndControlChars() {
+        val original = "line1\nline2\r\nline3\ttabbed"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripOnlySpecialChars() {
+        val original = "?&=+#%"
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+
+    @Test
+    fun roundTripLongMixedString() {
+        val original = ("Hello World! " +
+                "Ünïcödé & symbols: <>\"/\\|?* " +
+                "CJK: 日本語 Emoji: 🚀").repeat(50)
+        assertEquals(original, original.encodeUrl().decodeUrl())
+    }
+}