Check the diagnostic's report without naming Maven Central's or the plugin portal's URL (#206)

Which URL a build reaches Maven Central and the Gradle Plugin Portal at depends on the machine. Where CI names a
mirror, as the Code Genome Project's builds do, the mirror stands in for both, and gradle(), gradleNoDefaultRepos()
and dependencyNotFound() failed there: gradle() found 3 rows instead of 4, the mirror counting once for both.

The tests now check the repositories they declare by URL, and Central and the plugin portal only by being reachable.
maven() forced empty settings, so it always pinged Maven Central itself; it now reaches Central through
MAVEN_CENTRAL_MIRROR_URL when that is set.

Author: jkschneider

src/test/java/org/openrewrite/java/dependencies/DependencyResolutionDiagnosticTest.java

@@ -17,6 +17,7 @@
 
 import org.junit.jupiter.api.Test;
 import org.openrewrite.DocumentExample;
+import org.openrewrite.ExecutionContext;
 import org.openrewrite.InMemoryExecutionContext;
 import org.openrewrite.Parser;
 import org.openrewrite.java.dependencies.table.RepositoryAccessibilityReport;
@@ -27,12 +28,18 @@
 
 import java.io.ByteArrayInputStream;
 import java.nio.file.Path;
+import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.openrewrite.gradle.Assertions.buildGradle;
 import static org.openrewrite.gradle.toolingapi.Assertions.withToolingApi;
 import static org.openrewrite.maven.Assertions.pomXml;
 
+/**
+ * Which URL Maven Central and the Gradle Plugin Portal are reached at depends on the machine the tests run on: where
+ * CI names a mirror in MAVEN_CENTRAL_MIRROR_URL, the mirror stands in for both. So these tests check the repositories
+ * they declare themselves by URL, and Central and the plugin portal only by being reachable.
+ */
 @SuppressWarnings("GroovyAssignabilityCheck")
 class DependencyResolutionDiagnosticTest implements RewriteTest {
 
@@ -68,15 +75,11 @@ void gradle() {
             // It is a limitation of the tooling API which prevents configuration-granularity error information from being collected.
             // So the GradleDependencyConfigurationErrors table will never be populated in unit tests.
             .dataTable(RepositoryAccessibilityReport.Row.class, rows -> {
-                assertThat(rows)
-                        .hasSize(4)
-                        .contains(
-                  new RepositoryAccessibilityReport.Row("https://repo.maven.apache.org/maven2", "", "", 200, "", ""));
                 assertThat(rows).filteredOn(row -> row.getUri().startsWith("file:/") && "".equals(row.getPingExceptionMessage())).hasSize(1);
-                assertThat(rows).contains(
-                  new RepositoryAccessibilityReport.Row("https://plugins.gradle.org/m2", "", "", 200, "", ""));
                 assertThat(rows)
                   .filteredOn(row -> "https://nonexistent.moderne.io/maven2".equals(row.getUri()) && row.getPingHttpCode() == null).hasSize(1);
+                // Maven Central and the plugin portal, which are one row where a mirror stands in for both
+                assertThat(remote(rows)).hasSizeBetween(1, 2).allSatisfy(DependencyResolutionDiagnosticTest::reachable);
             }),
           //language=groovy
           buildGradle(
@@ -107,12 +110,14 @@ void gradleNoDefaultRepos() {
           spec -> spec.beforeRecipe(withToolingApi())
             // It is a limitation of the tooling API which prevents configuration-granularity error information from being collected.
             // So the GradleDependencyConfigurationErrors table will never be populated in unit tests.
-            .dataTable(RepositoryAccessibilityReport.Row.class, rows -> assertThat(rows)
-                    .hasSize(2)
-                    .contains(
-              new RepositoryAccessibilityReport.Row("https://plugins.gradle.org/m2", "", "", 200, "", ""))
-                    .contains(
-              new RepositoryAccessibilityReport.Row("https://nonexistent.moderne.io/maven2", "java.net.UnknownHostException", "nonexistent.moderne.io", null, "", ""))),
+            .dataTable(RepositoryAccessibilityReport.Row.class, rows -> {
+                assertThat(rows)
+                  .hasSize(2)
+                  .contains(
+                    new RepositoryAccessibilityReport.Row("https://nonexistent.moderne.io/maven2", "java.net.UnknownHostException", "nonexistent.moderne.io", null, "", ""));
+                // The plugin portal, which Gradle adds
+                assertThat(remote(rows)).singleElement().satisfies(DependencyResolutionDiagnosticTest::reachable);
+            }),
           //language=groovy
           buildGradle(
             """
@@ -182,19 +187,19 @@ void maven() {
           spec -> {
               // CI may inject ~/.m2/settings.xml with `<mirrorOf>*</mirrorOf>` to route Maven through a cache.
               // That rewrites the pom-declared `nonexistent` repo to the mirror URL, so neither Maven Central
-              // nor the test's `nonexistent.moderne.io` repo appear in the diagnostic. Force empty settings
-              // here so the recipe sees the pom-declared repositories directly.
+              // nor the test's `nonexistent.moderne.io` repo appear in the diagnostic. Use settings of the test's
+              // own here, so the recipe sees the pom-declared repositories directly.
               MavenExecutionContextView ctx = MavenExecutionContextView.view(new InMemoryExecutionContext());
-              ctx.setMavenSettings(new MavenSettings(null, null, null, null, null, null));
+              ctx.setMavenSettings(settingsMirroringOnlyCentral(ctx));
               spec
                 .executionContext(ctx)
                 .dataTable(RepositoryAccessibilityReport.Row.class, rows -> {
-                    assertThat(rows).contains(
-                      new RepositoryAccessibilityReport.Row("https://repo.maven.apache.org/maven2", "", "", 200, "", ""));
                     assertThat(rows).filteredOn(row -> row.getUri().startsWith("file:/") && "".equals(row.getPingExceptionMessage())).hasSize(1);
                     assertThat(rows).contains(
                       new RepositoryAccessibilityReport.Row("https://nonexistent.moderne.io/maven2", "java.net.UnknownHostException", "nonexistent.moderne.io", null, "", "")
                     );
+                    // Maven Central, which the recipe adds
+                    assertThat(remote(rows)).singleElement().satisfies(DependencyResolutionDiagnosticTest::reachable);
                 });
           },
           //language=xml
@@ -223,11 +228,14 @@ void dependencyNotFound() {
           spec -> spec.recipe(new DependencyResolutionDiagnostic("org.nonexistent", "nonexistent", "0"))
             .beforeRecipe(withToolingApi())
             .dataTable(RepositoryAccessibilityReport.Row.class, rows ->
-              assertThat(rows).contains(
-                new RepositoryAccessibilityReport.Row("https://repo.maven.apache.org/maven2",
-                  "", "", 200, "org.openrewrite.maven.MavenDownloadingException",
-                  "org.nonexistent:nonexistent:0 failed. Unable to download POM: org.nonexistent:nonexistent:0. Tried repositories:\nhttps://repo.maven.apache.org/maven2/: HTTP 404")
-              )
+              // Maven Central, which is reachable but has no such dependency
+              assertThat(rows).anySatisfy(row -> {
+                  reachable(row);
+                  assertThat(row.getDependencyResolveExceptionType()).isEqualTo("org.openrewrite.maven.MavenDownloadingException");
+                  assertThat(row.getDependencyResolveExceptionMessage())
+                    .startsWith("org.nonexistent:nonexistent:0 failed. Unable to download POM: org.nonexistent:nonexistent:0. Tried repositories:\n" + row.getUri())
+                    .endsWith(": HTTP 404");
+              })
             ),
           //language=groovy
           buildGradle(
@@ -242,4 +250,46 @@ void dependencyNotFound() {
           )
         );
     }
+
+    /** The rows of the repositories other than the local one and the one that doesn't exist. */
+    private static List<RepositoryAccessibilityReport.Row> remote(List<RepositoryAccessibilityReport.Row> rows) {
+        return rows.stream()
+          .filter(row -> !row.getUri().startsWith("file:/") && !row.getUri().contains("nonexistent.moderne.io"))
+          .toList();
+    }
+
+    private static void reachable(RepositoryAccessibilityReport.Row row) {
+        assertThat(row.getPingHttpCode()).as("what %s answered", row.getUri()).isEqualTo(200);
+        assertThat(row.getPingExceptionType()).as("what reaching %s threw", row.getUri()).isEmpty();
+    }
+
+    /**
+     * Settings with no mirror but one of Maven Central, the mirror CI names in MAVEN_CENTRAL_MIRROR_URL, _USERNAME and
+     * _PASSWORD, so that Central is reached as the rest of the build reaches it. With no mirror named, none at all.
+     */
+    private static MavenSettings settingsMirroringOnlyCentral(ExecutionContext ctx) {
+        if (System.getenv("MAVEN_CENTRAL_MIRROR_URL") == null) {
+            return new MavenSettings(null, null, null, null, null, null);
+        }
+        return MavenSettings.parse(new Parser.Input(Path.of("settings.xml"), () -> new ByteArrayInputStream(
+          //language=xml
+          """
+            <settings>
+                <servers>
+                    <server>
+                        <id>central-mirror</id>
+                        <username>${env.MAVEN_CENTRAL_MIRROR_USERNAME}</username>
+                        <password>${env.MAVEN_CENTRAL_MIRROR_PASSWORD}</password>
+                    </server>
+                </servers>
+                <mirrors>
+                    <mirror>
+                        <id>central-mirror</id>
+                        <mirrorOf>central</mirrorOf>
+                        <url>${env.MAVEN_CENTRAL_MIRROR_URL}</url>
+                    </mirror>
+                </mirrors>
+            </settings>
+            """.getBytes())), ctx);
+    }
 }