bazel: make //codepropertygraph:tests run the actual tests (#1870)

The target globbed src/main/scala and therefore ran 0 tests.

- use src/test/scala and ship src/test/resources as data
- add better-files (repin) and link the domain classes at runtime
- resolve test resources via the Bazel runfiles lookup (CpgRunfilesLocator,
  same mechanism as in joern); ProjectRoot.relativise remains the fallback
  for sbt/IDE only

Author: max-leuthaeuser

MODULE.bazel

@@ -2,6 +2,7 @@ module(name = "codepropertygraph")
 
 bazel_dep(name = "protobuf", version = "34.1")
 bazel_dep(name = "bazel_tooling")
+bazel_dep(name = "rules_java", version = "9.6.1")
 bazel_dep(name = "rules_jvm_external", version = "7.0")
 bazel_dep(name = "aspect_rules_lint", version = "2.5.2")
 bazel_dep(name = "buildifier_prebuilt", version = "8.5.1.2")
@@ -46,6 +47,7 @@ maven.install(
         "com.google.protobuf:protobuf-java:4.34.1",
         "com.lihaoyi:ujson_3:4.4.3",
         "com.lihaoyi:os-lib_3:0.11.4",
+        "com.github.pathikrit:better-files_3:3.9.2",
     ],
     excluded_artifacts = [
         # Exclude any scala libraries which might come in transitively.

codepropertygraph/BUILD

@@ -1,3 +1,4 @@
+load("@rules_java//java:java_library.bzl", "java_library")
 load("//bazel:scala.bzl", "scala_library", "scala_test")
 
 scala_library(
@@ -19,10 +20,32 @@ scala_library(
     ],
 )
 
+# We need to use the java_library rule because the dependency
+# @rules_java//java/runfiles brings in an annotation processor and
+# those only get picked up and executed by java_library and not
+# scala_library.
+java_library(
+    name = "tests_java",
+    testonly = True,
+    srcs = glob(["src/test/javaBazel/**/*.java"]),
+    deps = [
+        "@rules_java//java/runfiles",
+    ],
+)
+
 scala_test(
     name = "tests",
-    srcs = glob(["src/main/scala/**/*.scala"]),
+    srcs = glob(["src/test/scala/**/*.scala"]),
+    data = glob(["src/test/resources/**"]),
+    # The compile time domain classes are neverlink, so the tests need the linked variant at runtime.
+    runtime_deps = ["//schema:domainClassesLinked"],
     deps = [
         ":codepropertygraph",
+        ":tests_java",
+        "//schema:domainClassesNeverLinked",
+        "//schema:java_proto",
+        "@maven//:com_github_pathikrit_better_files_3",
+        "@maven//:io_joern_flatgraph_core_3",
+        "@maven//:io_joern_flatgraph_help_3",
     ],
 )

codepropertygraph/src/test/java/io/shiftleft/utils/CpgRunfilesLocatorJava.java

@@ -0,0 +1,14 @@
+package io.shiftleft.utils;
+
+import java.io.IOException;
+import java.util.Optional;
+
+// This class is only used in the sbt build where the runfiles location is not a
+// build concept and thus handled on a case by case basis.
+// The sbt implementation just returns empty to indicate that the runfiles
+// cannot be retrieved.
+class CpgRunfilesLocatorJava {
+  static Optional<String> resolve(String path) throws IOException {
+    return Optional.empty();
+  }
+}

codepropertygraph/src/test/javaBazel/io/shiftleft/utils/CpgRunfilesLocatorJava.java

@@ -0,0 +1,25 @@
+package io.shiftleft.utils;
+
+import com.google.devtools.build.runfiles.AutoBazelRepository;
+import com.google.devtools.build.runfiles.Runfiles;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+
+// This class is only part of the Bazel build.
+@AutoBazelRepository
+class CpgRunfilesLocatorJava {
+  static Optional<String> resolve(String path) throws IOException {
+    // The AutoBazelRepository_CpgRunfilesLocatorJava class is auto generated based on the @AutoBazelRepository
+    // annotation.
+    Runfiles runfiles = Runfiles.preload().withSourceRepository(AutoBazelRepository_CpgRunfilesLocatorJava.NAME);
+    String resolvedPath = runfiles.rlocation(path);
+    if (resolvedPath != null && Files.exists(Path.of(resolvedPath))) {
+      return Optional.of(resolvedPath);
+    } else {
+      return Optional.empty();
+    }
+  }
+}

codepropertygraph/src/test/scala/io/shiftleft/codepropertygraph/cpgloading/CpgLoaderTests.scala

@@ -3,7 +3,7 @@ package io.shiftleft.codepropertygraph.cpgloading
 import flatgraph.{Accessors, DiffGraphApplier}
 import io.shiftleft.codepropertygraph.generated.Cpg
 import io.shiftleft.codepropertygraph.generated.nodes.NewMethod
-import io.shiftleft.utils.{ProjectRoot, TempFileCopy}
+import io.shiftleft.utils.{CpgRunfilesLocator, ProjectRoot, TempFileCopy}
 import io.shiftleft.codepropertygraph.generated.nodes.Type
 import org.scalatest.BeforeAndAfterAll
 import org.scalatest.matchers.should.Matchers
@@ -37,7 +37,7 @@ class CpgLoaderTests extends AnyWordSpec with Matchers with BeforeAndAfterAll {
   }
 
   "allow loading of CPG in overflowdb format" in {
-    val odbCpg = ProjectRoot.relativise("codepropertygraph/src/test/resources/cpg.odb")
+    val odbCpg = testResource("cpg.odb")
     Using.resource(CpgLoader.load(odbCpg)) { cpg =>
       cpg.graph.nodes("METHOD").size shouldBe 7
     }
@@ -75,7 +75,13 @@ class CpgLoaderTests extends AnyWordSpec with Matchers with BeforeAndAfterAll {
   }
 
   /** this test graph was created by c2cpg for https://github.com/joernio/joern/blob/master/tests/code/c/test.c */
-  val flatgraphCpg = Paths.get(ProjectRoot.relativise("codepropertygraph/src/test/resources/cpg.fg"))
+  val flatgraphCpg = Paths.get(testResource("cpg.fg"))
+
+  /** Bazel runfiles lookup with fallback to the project root relative path (sbt, IDE) */
+  private def testResource(name: String): String =
+    CpgRunfilesLocator
+      .resolve(s"codepropertygraph/codepropertygraph/src/test/resources/$name")
+      .getOrElse(ProjectRoot.relativise(s"codepropertygraph/src/test/resources/$name"))
 
   /** flatgraph writes to this file on 'close', so we'll create a temporary copy */
   private def temporaryFlatgraphCpg(): TempFileCopy =

codepropertygraph/src/test/scala/io/shiftleft/utils/CpgRunfilesLocator.scala

@@ -0,0 +1,11 @@
+package io.shiftleft.utils
+
+import scala.jdk.OptionConverters.RichOptional
+
+/** Resolves files via the Bazel runfiles lookup. Only meant for tests inside of this repository. The sbt build always
+  * returns None, so callers need to fall back to [[ProjectRoot.relativise]].
+  */
+private[shiftleft] object CpgRunfilesLocator {
+  def resolve(path: String): Option[String] =
+    CpgRunfilesLocatorJava.resolve(path).toScala
+}

maven_install.json

@@ -1,6 +1,7 @@
 {
   "__AUTOGENERATED_FILE_DO_NOT_MODIFY_THIS_FILE_MANUALLY": "THERE_IS_NO_DATA_ONLY_ZUUL",
   "__INPUT_ARTIFACTS_HASH": {
+    "com.github.pathikrit:better-files_3": 2078137804,
     "com.google.code.findbugs:jsr305": 495355163,
     "com.google.code.gson:gson": 597770368,
     "com.google.errorprone:error_prone_annotations": -1035138750,
@@ -22,6 +23,8 @@
   "__RESOLVED_ARTIFACTS_HASH": {
     "com.github.luben:zstd-jni": 1886873774,
     "com.github.luben:zstd-jni:jar:sources": -1190847340,
+    "com.github.pathikrit:better-files_3": -730147472,
+    "com.github.pathikrit:better-files_3:jar:sources": -1753499885,
     "com.github.scopt:scopt_3": 148843063,
     "com.github.scopt:scopt_3:jar:sources": 776003799,
     "com.google.code.findbugs:jsr305": 870839855,
@@ -97,6 +100,13 @@
       },
       "version": "1.5.7-11"
     },
+    "com.github.pathikrit:better-files_3": {
+      "shasums": {
+        "jar": "136c1770a63aa33b2710745bf7f8441cbbe0eeef0cab6b832bd0a46804158989",
+        "sources": "5a3d4cc0c63605353b1c528abfdc180ae4d74b6c50d6693eee4389dcec923e61"
+      },
+      "version": "3.9.2"
+    },
     "com.github.scopt:scopt_3": {
       "shasums": {
         "jar": "7cfb80743b761b3df8630a818265eb91fd93cd77b32ed5ebd6fba1bb7cff6a3f",
@@ -385,6 +395,9 @@
       "com.github.luben.zstd",
       "com.github.luben.zstd.util"
     ],
+    "com.github.pathikrit:better-files_3": [
+      "better.files"
+    ],
     "com.github.scopt:scopt_3": [
       "scopt"
     ],
@@ -760,6 +773,8 @@
     "https://repo1.maven.org/maven2/": [
       "com.github.luben:zstd-jni",
       "com.github.luben:zstd-jni:jar:sources",
+      "com.github.pathikrit:better-files_3",
+      "com.github.pathikrit:better-files_3:jar:sources",
       "com.github.scopt:scopt_3",
       "com.github.scopt:scopt_3:jar:sources",
       "com.google.code.findbugs:jsr305",