gazelle: Fail when errors occur (#202)

Intead of introducing a fail-fast, leverage the lifecycle to fail the
extension when errors that would produce invalid build files occur.

java/gazelle/lang.go

@@ -1,6 +1,7 @@
 package gazelle
 
 import (
+	"context"
 	"os"
 
 	"github.com/bazel-contrib/rules_jvm/java/gazelle/private/java"
@@ -17,6 +18,7 @@ import (
 // javaLang is a language.Language implementation for Java.
 type javaLang struct {
 	config.Configurer
+	language.BaseLifecycleManager
 	resolve.Resolver
 
 	parser        *javaparser.Runner
@@ -27,6 +29,12 @@ type javaLang struct {
 	// javaPackageCache is used for module granularity support
 	// Key is the path to the java package from the Bazel workspace root.
 	javaPackageCache map[string]*java.Package
+
+	// hasHadErrors triggers the extension to fail at destroy time.
+	//
+	// this is used to return != 0 when some errors during the generation were
+	// raised that will create invalid build files.
+	hasHadErrors bool
 }
 
 func NewLanguage() language.Language {
@@ -38,7 +46,7 @@ func NewLanguage() language.Language {
 		Caller().
 		Logger().
 		Level(goLevel)
-	logger.Print("creating java language")
+	logger.Debug().Msg("creating java language")
 
 	l := javaLang{
 		logger:           logger,
@@ -138,3 +146,9 @@ func (l javaLang) Fix(c *config.Config, f *rule.File) {}
 func (l javaLang) DoneGeneratingRules() {
 	l.parser.ServerManager().Shutdown()
 }
+
+func (l javaLang) AfterResolvingDeps(_ context.Context) {
+	if l.hasHadErrors {
+		l.logger.Fatal().Msg("the java extension encontered errors that will create invalid build files")
+	}
+}

java/gazelle/private/maven/resolver.go

@@ -1,7 +1,6 @@
 package maven
 
 import (
-	"errors"
 	"fmt"
 
 	"github.com/bazel-contrib/rules_jvm/java/gazelle/private/bazel"
@@ -11,6 +10,25 @@ import (
 	"github.com/rs/zerolog"
 )
 
+// NoExternalImportsError represents the error when no external imports are found.
+type NoExternalImportsError struct {
+	PackageName string
+}
+
+func (e *NoExternalImportsError) Error() string {
+	return fmt.Sprintf("no external imports found for %s", e.PackageName)
+}
+
+// MultipleExternalImportsError represents the error when multiple possible external imports are found.
+type MultipleExternalImportsError struct {
+	PackageName      string
+	PossiblePackages []string
+}
+
+func (e *MultipleExternalImportsError) Error() string {
+	return fmt.Sprintf("multiple external imports found for %s; %v", e.PackageName, e.PossiblePackages)
+}
+
 type Resolver interface {
 	Resolve(pkg types.PackageName, excludedArtifacts map[string]struct{}, mavenRepositoryName string) (label.Label, error)
 }
@@ -54,7 +72,7 @@ func NewResolver(installFile string, logger zerolog.Logger) (Resolver, error) {
 func (r *resolver) Resolve(pkg types.PackageName, excludedArtifacts map[string]struct{}, mavenRepositoryName string) (label.Label, error) {
 	v, found := r.data.Get(pkg.Name)
 	if !found {
-		return label.NoLabel, fmt.Errorf("package not found: %s", pkg)
+		return label.NoLabel, &NoExternalImportsError{PackageName: pkg.Name}
 	}
 
 	var filtered []string
@@ -67,7 +85,7 @@ func (r *resolver) Resolve(pkg types.PackageName, excludedArtifacts map[string]s
 
 	switch len(filtered) {
 	case 0:
-		return label.NoLabel, errors.New("no external imports")
+		return label.NoLabel, &NoExternalImportsError{PackageName: pkg.Name}
 
 	case 1:
 		var ret string
@@ -78,12 +96,10 @@ func (r *resolver) Resolve(pkg types.PackageName, excludedArtifacts map[string]s
 		return label.Parse(ret)
 
 	default:
-		r.logger.Error().Msg("Append one of the following to BUILD.bazel:")
-		for _, k := range filtered {
-			r.logger.Error().Msgf("# gazelle:resolve java %s %s", pkg.Name, k)
+		return label.NoLabel, &MultipleExternalImportsError{
+			PackageName:      pkg.Name,
+			PossiblePackages: filtered,
 		}
-
-		return label.NoLabel, errors.New("many possible imports")
 	}
 }
 

java/gazelle/resolve.go

@@ -1,11 +1,13 @@
 package gazelle
 
 import (
+	"errors"
 	"fmt"
 	"sort"
 
 	"github.com/bazel-contrib/rules_jvm/java/gazelle/javaconfig"
 	"github.com/bazel-contrib/rules_jvm/java/gazelle/private/java"
+	"github.com/bazel-contrib/rules_jvm/java/gazelle/private/maven"
 	"github.com/bazel-contrib/rules_jvm/java/gazelle/private/sorted_set"
 	"github.com/bazel-contrib/rules_jvm/java/gazelle/private/types"
 	"github.com/bazelbuild/bazel-gazelle/config"
@@ -197,7 +199,22 @@ func (jr *Resolver) resolveSinglePackage(c *config.Config, pc *javaconfig.Config
 		return label.NoLabel, nil
 	}
 
-	if l, err := jr.lang.mavenResolver.Resolve(imp, pc.ExcludedArtifacts(), pc.MavenRepositoryName()); err == nil {
+	if l, err := jr.lang.mavenResolver.Resolve(imp, pc.ExcludedArtifacts(), pc.MavenRepositoryName()); err != nil {
+		var noExternal *maven.NoExternalImportsError
+		var multipleExternal *maven.MultipleExternalImportsError
+
+		if errors.As(err, &noExternal) {
+			// do not fail, the package might be provided elsewhere
+		} else if errors.As(err, &multipleExternal) {
+			jr.lang.logger.Error().Msg("Append one of the following to BUILD.bazel:")
+			for _, possible := range multipleExternal.PossiblePackages {
+				jr.lang.logger.Error().Msgf("# gazelle:resolve java %s %s", imp.Name, possible)
+			}
+			jr.lang.hasHadErrors = true
+		} else {
+			jr.lang.logger.Fatal().Err(err).Msg("maven resolver error")
+		}
+	} else {
 		return l, nil
 	}
 

java/gazelle/testdata/maven/WORKSPACE

@@ -10,6 +10,7 @@ http_archive(
 load("@rules_jvm_external//:defs.bzl", "maven_install")
 
 maven_install(
+    name = "vendor_java",
     artifacts = [
         "junit:junit:4.13.1",
         "com.google.guava:guava:30.0-jre",

java/gazelle/testdata/maven_with_collision/README.md

@@ -0,0 +1,5 @@
+# Maven with collision
+
+Make sure the java extension does fail on colliding packages in maven.
+
+Note that the maven_install.json file is manually crafted/invalid in order to simulate a collision on the `com.google.common.primitives` import.

java/gazelle/testdata/maven_with_collision/WORKSPACE

@@ -0,0 +1,27 @@
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "rules_jvm_external",
+    sha256 = "23fe83890a77ac1a3ee143e2306ec12da4a845285b14ea13cb0df1b1e23658fe",
+    strip_prefix = "rules_jvm_external-4.3",
+    urls = ["https://github.com/bazelbuild/rules_jvm_external/archive/refs/tags/4.3.tar.gz"],
+)
+
+load("@rules_jvm_external//:defs.bzl", "maven_install")
+
+maven_install(
+    artifacts = [
+        "junit:junit:4.13.1",
+        "com.google.guava:guava:30.0-jre",
+    ],
+    fetch_sources = True,
+    maven_install_json = "//:maven_install.json",
+    repositories = [
+        "http://uk.maven.org/maven2",
+        "https://jcenter.bintray.com/",
+    ],
+)
+
+load("@maven//:defs.bzl", "pinned_maven_install")
+
+pinned_maven_install()

java/gazelle/testdata/maven_with_collision/expectedExitCode.txt

@@ -0,0 +1 @@
+1

java/gazelle/testdata/maven_with_collision/expectedStderr.txt

@@ -0,0 +1,5 @@
+12:00AM ERR java/gazelle/resolve.go:XXX > Append one of the following to BUILD.bazel:
+12:00AM ERR java/gazelle/resolve.go:XXX > # gazelle:resolve java com.google.common.primitives @maven//:com_google_guava_guava
+12:00AM ERR java/gazelle/resolve.go:XXX > # gazelle:resolve java com.google.common.primitives @maven//:com_google_guava_guava_sources
+12:00AM WRN java/gazelle/resolve.go:XXX > Unable to find package for import in any dependency from rule=//src/main/java/com/example/myproject package=com.google.common.primitives
+12:00AM FTL java/gazelle/lang.go:XXX > the java extension encontered errors that will create invalid build files

java/gazelle/testdata/maven_with_collision/maven_install.json

@@ -0,0 +1,82 @@
+{
+    "dependency_tree": {
+        "dependencies": [
+            {
+                "coord": "com.google.guava:guava:30.0-jre",
+                "dependencies": [
+                    "com.google.code.findbugs:jsr305:3.0.2",
+                    "com.google.errorprone:error_prone_annotations:2.3.4",
+                    "com.google.guava:failureaccess:1.0.1",
+                    "com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava",
+                    "com.google.j2objc:j2objc-annotations:1.3",
+                    "org.checkerframework:checker-qual:3.5.0"
+                ],
+                "directDependencies": [
+                    "com.google.code.findbugs:jsr305:3.0.2",
+                    "com.google.errorprone:error_prone_annotations:2.3.4",
+                    "com.google.guava:failureaccess:1.0.1",
+                    "com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava",
+                    "com.google.j2objc:j2objc-annotations:1.3",
+                    "org.checkerframework:checker-qual:3.5.0"
+                ],
+                "file": "v1/https/jcenter.bintray.com/com/google/guava/guava/30.0-jre/guava-30.0-jre.jar",
+                "mirror_urls": [
+                    "http://uk.maven.org/maven2/com/google/guava/guava/30.0-jre/guava-30.0-jre.jar",
+                    "https://jcenter.bintray.com/com/google/guava/guava/30.0-jre/guava-30.0-jre.jar"
+                ],
+                "packages": [
+                    "com.google.common.annotations",
+                    "com.google.common.base",
+                    "com.google.common.base.internal",
+                    "com.google.common.cache",
+                    "com.google.common.collect",
+                    "com.google.common.escape",
+                    "com.google.common.eventbus",
+                    "com.google.common.graph",
+                    "com.google.common.hash",
+                    "com.google.common.html",
+                    "com.google.common.io",
+                    "com.google.common.math",
+                    "com.google.common.net",
+                    "com.google.common.primitives",
+                    "com.google.common.reflect",
+                    "com.google.common.util.concurrent",
+                    "com.google.common.xml",
+                    "com.google.thirdparty.publicsuffix"
+                ],
+                "sha256": "56b292df9ec29d102820c1fd7dd581cd749d5c416c7b3aeac008dbda3b984cc2",
+                "url": "https://jcenter.bintray.com/com/google/guava/guava/30.0-jre/guava-30.0-jre.jar"
+            },
+            {
+                "coord": "com.google.guava:guava:jar:sources:30.0-jre",
+                "dependencies": [
+                    "com.google.code.findbugs:jsr305:jar:sources:3.0.2",
+                    "com.google.errorprone:error_prone_annotations:jar:sources:2.3.4",
+                    "com.google.guava:failureaccess:jar:sources:1.0.1",
+                    "com.google.guava:listenablefuture:jar:sources:9999.0-empty-to-avoid-conflict-with-guava",
+                    "com.google.j2objc:j2objc-annotations:jar:sources:1.3",
+                    "org.checkerframework:checker-qual:jar:sources:3.5.0"
+                ],
+                "directDependencies": [
+                    "com.google.code.findbugs:jsr305:jar:sources:3.0.2",
+                    "com.google.errorprone:error_prone_annotations:jar:sources:2.3.4",
+                    "com.google.guava:failureaccess:jar:sources:1.0.1",
+                    "com.google.guava:listenablefuture:jar:sources:9999.0-empty-to-avoid-conflict-with-guava",
+                    "com.google.j2objc:j2objc-annotations:jar:sources:1.3",
+                    "org.checkerframework:checker-qual:jar:sources:3.5.0"
+                ],
+                "file": "v1/https/jcenter.bintray.com/com/google/guava/guava/30.0-jre/guava-30.0-jre-sources.jar",
+                "mirror_urls": [
+                    "http://uk.maven.org/maven2/com/google/guava/guava/30.0-jre/guava-30.0-jre-sources.jar",
+                    "https://jcenter.bintray.com/com/google/guava/guava/30.0-jre/guava-30.0-jre-sources.jar"
+                ],
+                "packages": [
+                    "com.google.common.primitives"
+                ],
+                "sha256": "daa8a245663f9027ae4b84239147d3439221839155a4d93cbab280c3e657a73d",
+                "url": "https://jcenter.bintray.com/com/google/guava/guava/30.0-jre/guava-30.0-jre-sources.jar"
+            }
+        ],
+        "version": "0.1.0"
+    }
+}

java/gazelle/testdata/maven_with_collision/src/main/java/com/example/myproject/App.java

@@ -0,0 +1,16 @@
+package com.example.myproject;
+
+import com.google.common.primitives.Ints;
+
+/** This application compares two numbers, using the Ints.compare method from Guava. */
+public class App {
+
+    public static int compare(int a, int b) {
+        return Ints.compare(a, b);
+    }
+
+    public static void main(String... args) throws Exception {
+        App app = new App();
+        System.out.println("Success: " + app.compare(2, 1));
+    }
+}

java/gazelle/testdata/maven_with_collision_and_resolve/BUILD.in

@@ -0,0 +1 @@
+# gazelle:resolve java com.google.common.primitives @maven//:com_google_guava_guava

java/gazelle/testdata/maven_with_collision_and_resolve/BUILD.out

@@ -0,0 +1 @@
+# gazelle:resolve java com.google.common.primitives @maven//:com_google_guava_guava

java/gazelle/testdata/maven_with_collision_and_resolve/README.md

@@ -0,0 +1,5 @@
+# Maven with collision and resolve
+
+Make sure the java extension does not fail on colliding packages in maven if the correct resolve directives are present.
+
+Note that the maven_install.json file is manually crafted/invalid in order to simulate a collision on the `com.google.common.primitives` import.

java/gazelle/testdata/maven_with_collision_and_resolve/WORKSPACE

@@ -0,0 +1,27 @@
+load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
+
+http_archive(
+    name = "rules_jvm_external",
+    sha256 = "23fe83890a77ac1a3ee143e2306ec12da4a845285b14ea13cb0df1b1e23658fe",
+    strip_prefix = "rules_jvm_external-4.3",
+    urls = ["https://github.com/bazelbuild/rules_jvm_external/archive/refs/tags/4.3.tar.gz"],
+)
+
+load("@rules_jvm_external//:defs.bzl", "maven_install")
+
+maven_install(
+    artifacts = [
+        "junit:junit:4.13.1",
+        "com.google.guava:guava:30.0-jre",
+    ],
+    fetch_sources = True,
+    maven_install_json = "//:maven_install.json",
+    repositories = [
+        "http://uk.maven.org/maven2",
+        "https://jcenter.bintray.com/",
+    ],
+)
+
+load("@maven//:defs.bzl", "pinned_maven_install")
+
+pinned_maven_install()