Fix NPE when no configuration is applied

Closes #1

.github/workflows/documentation.yml

@@ -3,8 +3,6 @@ on:
   push:
     branches:
       - main
-    paths:
-      - 'docs/**'
 jobs:
   generate_documentation:
     runs-on: ubuntu-18.04

plugin/src/functionalTest/groovy/me/champeau/gradle/igp/WellBehavedPluginFunctionalTest.groovy

@@ -0,0 +1,18 @@
+package me.champeau.gradle.igp
+
+import me.champeau.includegit.AbstractFunctionalTest
+
+class WellBehavedPluginFunctionalTest extends AbstractFunctionalTest {
+    def "can apply the plugin without any configuration"() {
+        withSample 'zeroconf'
+
+        when:
+        run 'help'
+
+        then:
+        tasks {
+            succeeded ':help'
+        }
+    }
+
+}

plugin/src/main/java/me/champeau/gradle/igp/internal/DefaultIncludeGitExtension.java

@@ -154,6 +154,9 @@ private void readCheckoutMetadata() {
     }
 
     public void writeCheckoutMetadata() {
+        if (checkoutMetadata == null) {
+            return;
+        }
         File metadataFile = getCheckoutsDirectory().file("checkouts.bin").get().getAsFile();
         File parentFile = metadataFile.getParentFile();
         parentFile.mkdirs();

samples/zeroconf/groovy/build.gradle

@@ -0,0 +1,7 @@
+plugins {
+    id 'java-library'
+}
+
+dependencies {
+    implementation 'com.acme.somelib:somelib1:0.0'
+}

samples/zeroconf/groovy/settings.gradle

@@ -0,0 +1,5 @@
+plugins {
+    id 'me.champeau.includegit'
+}
+
+rootProject.name = "zero"

samples/zeroconf/kotlin/build.gradle.kts

@@ -0,0 +1,7 @@
+plugins {
+    `java-library`
+}
+
+dependencies {
+    implementation("com.acme.somelib:somelib1:0.0")
+}

samples/zeroconf/kotlin/settings.gradle.kts

@@ -0,0 +1,7 @@
+import me.champeau.gradle.igp.gitRepositories
+
+plugins {
+    id("me.champeau.includegit")
+}
+
+rootProject.name = "zero"