Read package.json into extension #232

build.gradle.kts

@@ -38,6 +38,7 @@ repositories {
 }
 
 dependencies {
+    api("com.fasterxml.jackson.core:jackson-databind:2.13.2.2")
     testImplementation(platform("org.junit:junit-bom:5.6.2"))
     testImplementation("org.junit.jupiter:junit-jupiter-api")
     testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine")

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

@@ -25,6 +25,7 @@ class NodePlugin : Plugin<Project> {
     override fun apply(project: Project) {
         this.project = project
         val nodeExtension = NodeExtension.create(project)
+        project.extensions.create<PackageJsonExtension>(PackageJsonExtension.NAME, project)
         addGlobalTypes()
         addTasks()
         addNpmRule()

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

@@ -0,0 +1,67 @@
+package com.github.gradle.node
+
+import com.fasterxml.jackson.databind.JsonNode
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.gradle.api.Project
+import org.gradle.kotlin.dsl.property
+import org.gradle.util.GradleVersion
+
+/**
+ * Provides a parsed view of package.json
+ */
+open class PackageJsonExtension(project: Project) {
+
+    /**
+     * Raw JsonNode returned by Jackson, this may be removed in a future release
+     */
+    val node = project.objects.property<JsonNode>()
+
+    init {
+        if (GradleVersion.current() >= GradleVersion.version("6.1")) {
+            node.finalizeValueOnRead()
+        }
+        node.set(project.provider { project.file("package.json").let(ObjectMapper()::readTree) })
+    }
+
+    val name = project.provider { node.get().get("name")?.asText() }
+
+    val version = project.provider { node.get().get("version")?.asText() }
+
+    val description = project.provider { node.get().get("description")?.asText() }
+
+    val homepage = project.provider { node.get().get("homepage")?.asText() }
+
+    val license = project.provider { node.get().get("license")?.asText() }
+
+    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()
+    }
+
+    /**
+     * Get the boolean value of a given field
+     */
+    fun getBoolean(name: String): Boolean? {
+        return node.get().get(name)?.asBoolean()
+    }
+
+    /**
+     * Get the text value of a field containing nested objects
+     *
+     * e.g. <pre>{ "outer": { "inner": "nested } }</pre>
+     */
+    fun get(vararg name: String): String {
+        return name.fold(node.get()) { acc, next -> acc.get(next) }.asText()
+    }
+
+    companion object {
+        /**
+         * Extension name in Gradle
+         */
+        const val NAME = "package.json"
+    }
+}

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

@@ -0,0 +1,65 @@
+//file:noinspection GroovyPointlessBoolean
+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'() {
+        when:
+        temporaryFolder.newFile("package.json") << """
+            { "name": "test", "version": "1.10.2", "private": false }
+        """
+        project.apply plugin: 'com.github.node-gradle.node'
+        project.evaluate()
+
+        then:
+        def ext = project.extensions.getByName('package.json') as PackageJsonExtension
+        ext.name.get() == "test"
+        ext.version.get() == "1.10.2"
+        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") << """
+            { "name": "test", "version": "1.10.2", "private": false }
+        """
+        project.apply plugin: 'com.github.node-gradle.node'
+        project.evaluate()
+
+        then:
+        def ext = project.extensions.getByName('package.json') as PackageJsonExtension
+        ext.get("name") == "test"
+        ext.getBoolean("private") == false
+    }
+
+    def 'get nested attributes'() {
+        when:
+        temporaryFolder.newFile("package.json") << """
+            {
+            "upper": { "lower": { "end": "done" } }
+            }
+        """
+        project.apply plugin: 'com.github.node-gradle.node'
+        project.evaluate()
+
+        then:
+        def ext = project.extensions.getByName('package.json') as PackageJsonExtension
+        ext.get("upper", "lower", "end") == "done"
+    }
+}

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

@@ -0,0 +1,34 @@
+package com.github.gradle.node
+
+import com.github.gradle.AbstractIntegTest
+import com.github.gradle.RunWithMultipleGradleVersions
+import org.gradle.testkit.runner.TaskOutcome
+import org.junit.Assume
+
+@RunWithMultipleGradleVersions
+class PackageJsonExtension_integTest extends AbstractIntegTest {
+
+    def 'check standard attribute'() {
+        given:
+        Assume.assumeTrue(isConfigurationCacheEnabled())
+        copyResources("fixtures/npm-env/")
+        copyResources("fixtures/env/")
+        createFile("build.gradle") << """
+def nameProvider = project.extensions.getByName("${PackageJsonExtension.NAME}").name
+tasks.register('printPackageJsonName') {
+    inputs.property('name', nameProvider)
+    doLast {
+        println nameProvider.get()
+    }
+}
+"""
+
+        when:
+        def result1 = build(":printPackageJsonName")
+        def result2 = build(":printPackageJsonName")
+
+        then:
+        result1.task(":printPackageJsonName").outcome == TaskOutcome.SUCCESS
+        result2.task(":printPackageJsonName").outcome == TaskOutcome.SUCCESS
+    }
+}