Convert Json and JsonTest to Kotlin (#1394)

Author: tdchow

PayPal/src/main/java/com/braintreepayments/api/paypal/PayPalClient.kt

@@ -251,10 +251,10 @@ class PayPalClient internal constructor(
         val paymentType = Json.optString(metadata, "payment-type", "unknown")
         val isBillingAgreement = paymentType.equals("billing-agreement", ignoreCase = true)
         val tokenKey = if (isBillingAgreement) "ba_token" else "token"
-        val switchInitiatedTime = Uri.parse(approvalUrl).getQueryParameter("switch_initiated_time")
+        val switchInitiatedTime = approvalUrl?.toUri()?.getQueryParameter("switch_initiated_time")
         val isAppSwitchFlow = !switchInitiatedTime.isNullOrEmpty()
 
-        val contextId = approvalUrl.toUri().getQueryParameter(tokenKey)?.takeIf { it.isNotEmpty() }
+        val contextId = approvalUrl?.toUri()?.getQueryParameter(tokenKey)?.takeIf { it.isNotEmpty() }
         val analyticsEventParams = AnalyticsEventParams(
             contextId = contextId,
             isVaultRequest = isVaultRequest,
@@ -305,16 +305,16 @@ class PayPalClient internal constructor(
     )
     private fun parseUrlResponseData(
         uri: Uri,
-        successUrl: String,
+        successUrl: String?,
         approvalUrl: String?,
         tokenKey: String
     ): JSONObject {
         val status = uri.lastPathSegment
-        if (Uri.parse(successUrl).lastPathSegment != status) {
+        if (successUrl?.toUri()?.lastPathSegment != status) {
             throw UserCanceledException("User canceled PayPal.")
         }
 
-        val requestXoToken = Uri.parse(approvalUrl).getQueryParameter(tokenKey)
+        val requestXoToken = approvalUrl?.toUri()?.getQueryParameter(tokenKey)
         val responseXoToken = uri.getQueryParameter(tokenKey)
         if (TextUtils.equals(requestXoToken, responseXoToken)) {
             val client = JSONObject().apply {

SharedUtils/src/androidTest/java/com/braintreepayments/api/sharedutils/JsonTest.java

@@ -0,0 +1,45 @@
+package com.braintreepayments.api.sharedutils
+
+import androidx.test.internal.runner.junit4.AndroidJUnit4ClassRunner
+import org.json.JSONException
+import org.json.JSONObject
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+
+@RunWith(AndroidJUnit4ClassRunner::class)
+class JsonTest {
+
+    private lateinit var json: JSONObject
+
+    @Before
+    @Throws(JSONException::class)
+    fun setup() {
+        json = JSONObject("{\"key\":null}")
+    }
+
+    @Test
+    fun android_optString_returnsIncorrectNullValue() {
+        assertEquals("null", json.optString("key"))
+    }
+
+    @Test
+    fun optString_returnsCorrectNullValue() {
+        assertNull(Json.optString(json, "key", null))
+    }
+
+    @Test
+    fun optString_returnsFallback() {
+        assertEquals("fallback", Json.optString(json, "key", "fallback"))
+    }
+
+    @Test
+    @Throws(JSONException::class)
+    fun optString_returnsValue() {
+        json = JSONObject("{\"key\":\"value\"}")
+
+        assertEquals("value", Json.optString(json, "key", "value"))
+    }
+}

SharedUtils/src/androidTest/java/com/braintreepayments/api/sharedutils/JsonTest.kt

@@ -0,0 +1,73 @@
+package com.braintreepayments.api.sharedutils
+
+import androidx.annotation.RestrictTo
+import org.json.JSONObject
+
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+object Json {
+
+    /**
+     * Returns the value mapped by `name` from the given `json` object as a [String], or the provided nullable
+     * `fallback`.
+     *
+     * If the `json` object is null, the `name` is null, or the value mapped by `name` is null, the provided nullable
+     * `fallback` value is returned.
+     * This works around the issue where `JSONObject.optString` returns the string "null" for null values.
+     *
+     * @param json The [JSONObject] to query, or null.
+     * @param name The key to look up in the [JSONObject], or null.
+     * @param fallback The nullable fallback value to return if the mapping does not exist or is null.
+     * @return The mapped [String] value, or the nullable `fallback` if not found.
+     */
+    fun optString(json: JSONObject?, name: String?, fallback: String?): String? {
+        return if (json == null || name == null || json.isNull(name)) {
+            fallback
+        } else {
+            if (fallback != null) {
+                json.optString(name, fallback)
+            } else {
+                val result = json.optString(name)
+                if (result.isEmpty() && json.isNull(name)) null else result
+            }
+        }
+    }
+
+    /**
+     * Returns the value mapped by `name` from the given `json` object as a non-null [String].
+     *
+     * If the `json` object is null, the `name` is null, or the value mapped by `name` is null,
+     * the provided non-null `fallback` value is returned.
+     *
+     * @param json The [JSONObject] to query, or null.
+     * @param name The key to look up in the [JSONObject], or null.
+     * @param fallback The non-null fallback value to return if the mapping does not exist or is null.
+     * @return The mapped [String] value, or the non-null `fallback` if not found.
+     */
+    @JvmName("optStringNonNull")
+    fun optString(json: JSONObject?, name: String?, fallback: String): String {
+        return if (json == null || name == null || json.isNull(name)) {
+            fallback
+        } else {
+            json.optString(name, fallback)
+        }
+    }
+
+    /**
+     * Returns the value mapped by `name` from the given `json` object as a [Boolean], or the provided fallback value.
+     *
+     * If the `json` object is null, the `name` is null, or the value mapped by `name` is null, the provided fallback
+     * value is returned.
+     *
+     * @param json The [JSONObject] to query, or null.
+     * @param name The key to look up in the [JSONObject], or null.
+     * @param fallback The fallback value to return if the mapping does not exist or is null.
+     * @return The mapped [Boolean] value, or the fallback if not found.
+     */
+    fun optBoolean(json: JSONObject?, name: String?, fallback: Boolean): Boolean {
+        return if (json == null || name == null || json.isNull(name)) {
+            fallback
+        } else {
+            json.optBoolean(name, fallback)
+        }
+    }
+}