diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index b3218768..e579a1f9 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -158,9 +158,10 @@ dependencies {
     implementation("androidx.room:room-runtime:2.3.0")
     kapt("androidx.room:room-compiler:2.3.0")
 
-    testImplementation("io.kotest:kotest-runner-junit5:5.0.0.M2")
-    testImplementation("io.kotest:kotest-assertions-core:5.0.0.M2")
-    testImplementation("io.kotest:kotest-property:5.0.0.M2")
+    testImplementation("io.kotest:kotest-runner-junit5:4.6.3")
+    testImplementation("io.kotest:kotest-assertions-core:4.6.3")
+    testImplementation("io.kotest:kotest-property:4.6.3")
+    testImplementation("io.kotest.extensions:kotest-extensions-robolectric:0.4.0")
 
     androidTestImplementation("androidx.test.ext", "junit", "1.1.2")
     androidTestImplementation("androidx.test.espresso", "espresso-core", "3.3.0")
diff --git a/app/src/main/java/dev/patrickgold/florisboard/res/ext/ExtensionAuthor.kt b/app/src/main/java/dev/patrickgold/florisboard/res/ext/ExtensionAuthor.kt
index 9a0f7cde..3ce8e903 100644
--- a/app/src/main/java/dev/patrickgold/florisboard/res/ext/ExtensionAuthor.kt
+++ b/app/src/main/java/dev/patrickgold/florisboard/res/ext/ExtensionAuthor.kt
@@ -27,25 +27,31 @@ import kotlinx.serialization.encoding.Encoder
 import kotlin.math.min
 
 @Serializable(with = ExtensionAuthorSerializer::class)
-class ExtensionAuthor(
+data class ExtensionAuthor(
     val name: String,
     val email: String? = null,
     val url: FlorisRef? = null,
 ) {
     companion object {
+        private val ValidationRegex = """^\s*[\p{L}\d._-][\p{L}\d\s._-]*(<[^<>]+>)?\s*(\([^()]+\))?\s*${'$'}""".toRegex()
+
         fun from(str: String): ExtensionAuthor? {
-            if (str.isBlank()) {
+            if (str.isBlank() || !ValidationRegex.matches(str)) {
                 return null
             }
-            val emailStart = str.indexOf('<').let { if (it < 0) str.length else it } + 1
-            val emailEnd = str.indexOf('>').let { if (it < 0) str.length else it } - 1
-            val urlStart = str.indexOf('(').let { if (it < 0) str.length else it } + 1
-            val urlEnd = str.indexOf(')').let { if (it < 0) str.length else it } - 1
+            val emailStart = str.indexOf('<').let { if (it < 0) str.length else (it + 1) }
+            val emailEnd = str.indexOf('>').let { if (it < 0) str.length else it }
+            val urlStart = str.indexOf('(').let { if (it < 0) str.length else (it + 1) }
+            val urlEnd = str.indexOf(')').let { if (it < 0) str.length else it }
             val nameStart = 0
-            val nameEnd = (min(emailStart, urlStart) - 2).coerceIn(str.indices)
-            val name = str.substring(nameStart..nameEnd).trim()
-            val email = str.substring(emailStart..emailEnd).trim().takeIf { it.isNotBlank() }
-            val url = str.substring(urlStart..urlEnd).trim().takeIf { it.isNotBlank() }
+            val nameEnd = if (emailStart == str.length && urlStart == str.length) {
+                str.length
+            } else {
+                (min(emailStart, urlStart) - 1)
+            }
+            val name = str.substring(nameStart, nameEnd).trim()
+            val email = str.substring(emailStart, emailEnd).trim().takeIf { it.isNotBlank() }
+            val url = str.substring(urlStart, urlEnd).trim().takeIf { it.isNotBlank() }
             return ExtensionAuthor(name, email, url?.let { FlorisRef.from(it) })
         }
 
@@ -59,7 +65,7 @@ class ExtensionAuthor(
         if (email != null && email.isNotBlank()) {
             append(" <$email>")
         }
-        if (url != null && url.isValid) {
+        if (url != null) {
             append(" ($url)")
         }
     }
diff --git a/app/src/test/java/dev/patrickgold/florisboard/res/ext/ExtensionAuthorTest.kt b/app/src/test/java/dev/patrickgold/florisboard/res/ext/ExtensionAuthorTest.kt
new file mode 100644
index 00000000..f809a098
--- /dev/null
+++ b/app/src/test/java/dev/patrickgold/florisboard/res/ext/ExtensionAuthorTest.kt
@@ -0,0 +1,66 @@
+package dev.patrickgold.florisboard.res.ext
+
+import android.app.Application
+import dev.patrickgold.florisboard.res.FlorisRef
+import io.kotest.core.spec.style.FreeSpec
+import io.kotest.extensions.robolectric.RobolectricTest
+import io.kotest.matchers.shouldBe
+
+@RobolectricTest(application = Application::class)
+class ExtensionAuthorTest : FreeSpec({
+    val validAuthorPairs = listOf(
+        "Jane Doe" to ExtensionAuthor(name = "Jane Doe"),
+        "jane123" to ExtensionAuthor(name = "jane123"),
+        "__jane__" to ExtensionAuthor(name = "__jane__"),
+        "jane.doe" to ExtensionAuthor(name = "jane.doe"),
+        "Jane Doe <jane.doe@gmail.com>" to ExtensionAuthor(name = "Jane Doe", email = "jane.doe@gmail.com"),
+        "Jane Doe (jane-doe.com)" to ExtensionAuthor(name = "Jane Doe", url = FlorisRef.from("jane-doe.com")),
+        "Jane Doe <jane.doe@gmail.com> (jane-doe.com)" to ExtensionAuthor(name = "Jane Doe", email = "jane.doe@gmail.com", url = FlorisRef.from("jane-doe.com")),
+    )
+
+    "Test ExtensionAuthor.from()" - {
+        "With valid, well-formatted input" - {
+            validAuthorPairs.forEach { (authorStr, authorObj) ->
+                "`$authorStr`" {
+                    ExtensionAuthor.from(authorStr) shouldBe authorObj
+                }
+            }
+        }
+
+        "With valid, ill-formatted input" - {
+            listOf(
+                "  Jane Doe " to ExtensionAuthor(name = "Jane Doe"),
+                " jane123" to ExtensionAuthor(name = "jane123"),
+                "  Jane Doe    <jane.doe@gmail.com>     " to ExtensionAuthor(name = "Jane Doe", email = "jane.doe@gmail.com"),
+            ).forEach { (authorStr, authorObj) ->
+                "`$authorStr`" {
+                    ExtensionAuthor.from(authorStr) shouldBe authorObj
+                }
+            }
+        }
+
+        "With invalid input" - {
+            listOf(
+                "",
+                " ",
+                "<jane.doe@gmail.com>",
+                " <jane.doe@gmail.com>",
+                "<jane.doe@gmail.com> (jane-doe.com)",
+                "Jane Doe <<jane.doe@gmail.com>> ((jane-doe.com))",
+                "Jane Doe <jane.doe@gmail.com) (jane-doe.com)",
+            ).forEach { authorStr ->
+                "`$authorStr` should be null" {
+                    ExtensionAuthor.from(authorStr) shouldBe null
+                }
+            }
+        }
+    }
+
+    "Test ExtensionAuthor.toString()" - {
+        validAuthorPairs.forEach { (authorStr, authorObj) ->
+            "`$authorStr`" {
+                authorObj.toString() shouldBe authorStr
+            }
+        }
+    }
+})