[FGP Kotlin conversion] Convert Deeplink and IntentFilterCheck (#161835)

Converts `Deeplink` and `IntentFilterCheck` from Groovy to Kotlin, and
pulls them out to their own files. Also writes a test for the equals
method for `Deeplink`, as it is a custom equals method.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [ ] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [ ] All existing and new tests are passing.

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[Tree Hygiene]:
https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md
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[Features we expect every widget to implement]:
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[breaking change policy]:
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[Discord]:
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[Data Driven Fixes]:
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---------

Co-authored-by: Gray Mackall <mackall@google.com>

packages/flutter_tools/gradle/src/main/groovy/flutter.groovy

@@ -5,6 +5,8 @@
 
 import com.android.build.OutputFile
 import com.flutter.gradle.BaseApplicationNameHandler
+import com.flutter.gradle.Deeplink
+import com.flutter.gradle.IntentFilterCheck
 import groovy.json.JsonGenerator
 import groovy.xml.QName
 import java.nio.file.Paths
@@ -546,7 +548,7 @@ class FlutterPlugin implements Plugin<Project> {
                                     schemes.each { scheme ->
                                         hosts.each { host ->
                                             paths.each { path ->
-                                                appLinkSettings.deeplinks.add(new Deeplink(scheme: scheme, host: host, path: path, intentFilterCheck: intentFilterCheck))
+                                                appLinkSettings.deeplinks.add(new Deeplink(scheme, host, path, intentFilterCheck))
                                             }
                                         }
                                     }
@@ -1572,31 +1574,6 @@ class AppLinkSettings {
 
 }
 
-class IntentFilterCheck {
-
-    boolean hasAutoVerify
-    boolean hasActionView
-    boolean hasDefaultCategory
-    boolean hasBrowsableCategory
-
-}
-
-class Deeplink {
-    String scheme, host, path
-    IntentFilterCheck intentFilterCheck
-    boolean equals(Object o) {
-        if (o == null) {
-            throw new NullPointerException()
-        }
-        if (o.getClass() != getClass()) {
-            return false
-        }
-        return scheme == o.scheme &&
-                host == o.host &&
-                path == o.path
-    }
-}
-
 abstract class BaseFlutterTask extends DefaultTask {
 
     @Internal

packages/flutter_tools/gradle/src/main/kotlin/Deeplink.kt

@@ -0,0 +1,27 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package com.flutter.gradle
+
+// TODO(gmackall): Identify which of these can be val instead of var.
+class Deeplink(var scheme: String?, var host: String?, var path: String?, var intentFilterCheck: IntentFilterCheck?) {
+    // TODO(gmackall): This behavior was kept identical to the original Groovy behavior as part of
+    // the Groovy->Kotlin conversion, but should be changed once the conversion is complete.
+    override fun equals(other: Any?): Boolean {
+        if (other == null) {
+            throw NullPointerException()
+        }
+        if (other.javaClass != javaClass) {
+            return false
+        }
+        val otherAsDeeplink = other as Deeplink
+        return scheme == otherAsDeeplink.scheme &&
+            host == otherAsDeeplink.host &&
+            path == otherAsDeeplink.path
+    }
+
+    override fun hashCode(): Int {
+        return scheme.hashCode() + host.hashCode() + path.hashCode()
+    }
+}

packages/flutter_tools/gradle/src/main/kotlin/IntentFilterCheck.kt

@@ -0,0 +1,13 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package com.flutter.gradle
+
+class IntentFilterCheck {
+    // TODO(gmackall): Identify which of these can be val instead of var.
+    var hasAutoVerify = false
+    var hasActionView = false
+    var hasDefaultCategory = false
+    var hasBrowsableCategory = false
+}

packages/flutter_tools/gradle/src/test/kotlin/DeeplinkTest.kt

@@ -0,0 +1,41 @@
+package com.flutter.gradle
+
+import org.gradle.internal.impldep.org.junit.Assert.assertThrows
+import kotlin.test.Test
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class DeeplinkTest {
+    @Test
+    fun `equals should return true for equal objects`() {
+        val deeplink1 = Deeplink("scheme1", "host1", "path1", null)
+        val deeplink2 = Deeplink("scheme1", "host1", "path1", null)
+
+        assertTrue { deeplink1 == deeplink2 }
+    }
+
+    @Test
+    fun `equals should return false for unequal objects`() {
+        val deeplink1 = Deeplink("scheme1", "host1", "path1", null)
+        val deeplink2 = Deeplink("scheme2", "host2", "path2", null)
+
+        assertFalse { deeplink1 == deeplink2 }
+    }
+
+    @Test
+    fun `equals should return false for other of different type`() {
+        val deeplink1 = Deeplink("scheme1", "host1", "path1", null)
+        val notADeeplink = 5
+
+        assertFalse { deeplink1.equals(notADeeplink) }
+    }
+
+    @Suppress("UnusedEquals")
+    @Test
+    fun `equals should throw NullPointerException for null other`() {
+        val deeplink1 = Deeplink("scheme1", "host1", "path1", null)
+        val deeplink2 = null
+
+        assertThrows(NullPointerException::class.java, { deeplink1.equals(deeplink2) })
+    }
+}