Add null-safety to swap NPE for MissingValueException

Author: deepy

src/main/kotlin/com/github/gradle/node/PackageJsonExtension.kt

@@ -23,30 +23,30 @@ open class PackageJsonExtension(project: Project) {
         node.set(project.provider { project.file("package.json").let(ObjectMapper()::readTree) })
     }
 
-    val name = project.provider { node.get().get("name").asText() }
+    val name = project.provider { node.get().get("name")?.asText() }
 
-    val version = project.provider { node.get().get("version").asText() }
+    val version = project.provider { node.get().get("version")?.asText() }
 
-    val description = project.provider { node.get().get("description").asText() }
+    val description = project.provider { node.get().get("description")?.asText() }
 
-    val homepage = project.provider { node.get().get("homepage").asText() }
+    val homepage = project.provider { node.get().get("homepage")?.asText() }
 
-    val license = project.provider { node.get().get("license").asText() }
+    val license = project.provider { node.get().get("license")?.asText() }
 
-    val private = project.provider { node.get().get("private").asBoolean() }
+    val private = project.provider { node.get().get("private")?.asBoolean() }
 
     /**
      * Get the text value of a given field
      */
-    fun get(name: String): String {
-        return node.get().get(name).asText()
+    fun get(name: String): String? {
+        return node.get().get(name)?.asText()
     }
 
     /**
      * Get the boolean value of a given field
      */
-    fun getBoolean(name: String): Boolean {
-        return node.get().get(name).asBoolean()
+    fun getBoolean(name: String): Boolean? {
+        return node.get().get(name)?.asBoolean()
     }
 
     /**

src/test/groovy/com/github/gradle/node/PackageJsonExtensionTest.groovy

@@ -2,6 +2,7 @@
 package com.github.gradle.node
 
 import com.github.gradle.AbstractProjectTest
+import org.gradle.api.internal.provider.MissingValueException
 
 class PackageJsonExtensionTest extends AbstractProjectTest {
     def 'check standard attributes'() {
@@ -19,6 +20,20 @@ class PackageJsonExtensionTest extends AbstractProjectTest {
         ext.private.get() == false
     }
 
+    def 'get missing attribute'() {
+        when:
+        temporaryFolder.newFile("package.json") << """
+            { "name": "test", "version": "1.10.2", "private": false }
+        """
+        project.apply plugin: 'com.github.node-gradle.node'
+        project.evaluate()
+        def ext = project.extensions.getByName('package.json') as PackageJsonExtension
+        ext.homepage.get() == null
+
+        then:
+        thrown(MissingValueException)
+    }
+
     def 'get raw attributes'() {
         when:
         temporaryFolder.newFile("package.json") << """