Basic groovy_test support

--
Change-Id: I11d65bcacbb4a2037e29c6b3af7c4ff545636738
Reviewed-on: https://bazel-review.googlesource.com/#/c/1830/1
MOS_MIGRATED_REVID=101669018

3 files changed, 179 insertions, 25 deletions

diff --git a/tools/build_defs/groovy/README.md b/tools/build_defs/groovy/README.md
index e881a15510..a4d42cef4b 100644
--- a/tools/build_defs/groovy/README.md
+++ b/tools/build_defs/groovy/README.md
@@ -16,10 +16,11 @@ libraries and vice-versa.
 <a name="setup"></a>
 ## Setup
 
-To be able to use the Groovy rules, you must make the Groovy binaries available
-to Bazel. The easiest way to do so is by copying the content of
-`groovy.WORKSPACE` to your workspace file and putting `groovy.BUILD` at the root
-or your workspace.
+To be able to use the Groovy rules, you must make the Groovy libraries and
+binaries available to Bazel. Groovy tests also require JUnit and Hamcrest to be
+available at a known location. The easiest way to do so is by copying the
+content of `groovy.WORKSPACE` to your workspace file and putting `groovy.BUILD`
+at the root of your workspace.
 
 <a name="basic-example"></a>
 ## Basic Example
@@ -30,16 +31,22 @@ application:
 ```
 [workspace]/
     WORKSPACE
-    app/
-        BUILD
-        GroovyApp.groovy
-    lib/
-        BUILD
-        GroovyLib.groovy
-        JavaLib.java
+    src/main/groovy/
+        app/
+            BUILD
+            GroovyApp.groovy
+        lib/
+            BUILD
+            GroovyLib.groovy
+            JavaLib.java
+    src/test/groovy/
+        lib/
+            BUILD
+            LibTest.groovy
 ```
 
-Then, to build the code under lib/, your `lib/BUILD` can look like this:
+Then, to build the code under src/main/groovy/lib/, your
+`src/main/groovy/lib/BUILD` can look like this:
 
 ```python
 load("/tools/build_rules/groovy/groovy", "groovy_library")
@@ -60,8 +67,8 @@ java_library(
 
 For simplicity, you can combine Groovy and Java sources into a single library
 using `groovy_and_java_library`. Note that this allows the Groovy code to
-reference the Java code, but not vice-versa. Your `lib/BUILD` file would then
-look like this:
+reference the Java code, but not vice-versa. Your `src/main/groovy/lib/BUILD`
+file would then look like this:
 
 ```python
 load("/tools/build_rules/groovy/groovy", "groovy_and_java_library")
@@ -72,7 +79,8 @@ groovy_and_java_library(
 )
 ```
 
-Finally, you can define a binary using `groovy_binary` as follows:
+To build the application under src/main/groovy/app, you can define a binary using
+`groovy_binary` as follows:
 
 ```python
 load("/tools/build_rules/groovy/groovy", "groovy_binary")
@@ -82,13 +90,32 @@ groovy_binary(
     srcs = glob(["*.groovy"]),
     main_class = "GroovyApp",
     deps = [
-         "//lib",
+         "//src/main/groovy/lib",
     ],
 )
 ```
 
-You can then build the application with `bazel build //app:GroovyApp` and run it
-with `bazel run //app:GroovyApp`.
+Finally, you can write tests in Groovy using `groovy_test`. The `srcs` of this
+rule will be converted into names of class files that are passed to JUnit. For
+this to work, the test sources must be under src/test/groovy or src/test/java.
+To build the test under src/test/groovy/lib, your BUILD file would look like
+this:
+
+```python
+load("/tools/build_defs/groovy/groovy", "groovy_test", "groovy_library")
+
+
+groovy_library(
+  name = "testlib",
+  srcs = glob(["*.groovy"]),
+)
+
+groovy_test(
+  name = "LibTest",
+  srcs = ["LibTest.groovy"],
+  deps = [":testlib"],
+)
+```
 
 <a name="reference"></a>
 ## Build Rule Reference [reference]
@@ -267,3 +294,60 @@ with `bazel run //app:GroovyApp`.
     </tr>
   </tbody>
 </table>
+
+<a name="groovy_test"></a>
+### `groovy_test`
+
+`groovy_binary(name, main_class, srcs, deps, **kwargs)`
+
+<table>
+  <thead>
+    <tr>
+      <th>Attribute</th>
+      <th>Description</th>
+    </tr>
+  </thead>
+  <tbody>
+    <tr>
+      <td><code>name</code></td>
+      <td>
+        <code>Name, required</code>
+        <p>A unique name for this rule.</p>
+      </td>
+    </tr>
+    <tr>
+      <td><code>srcs</code></td>
+      <td>
+        <code>List of labels, required</code>
+        <p>
+          List of .groovy source files whose names will be converted to classes
+          passed to JUnitCore.
+        </p>
+      </td>
+    </tr>
+    <tr>
+      <td><code>deps</code></td>
+      <td>
+        <code>List of labels or .jar files, optional</code>
+        <p>
+          List of libraries to be included on both the compile-time classpath
+          when building this test and on the runtime classpath when executing it.
+        </p>
+        <p>
+          These can be `groovy_library` targets, `java_library` targets,
+          `groovy_and_java_library` targets, or raw .jar files.
+        </p>
+      </td>
+    </tr>
+    <tr>
+      <td><code>jvm_flags</code></td>
+      <td>
+        <code>List of strings, optional</code>
+        <p>
+          A list of flags to embed in the wrapper script generated for running
+          this binary.
+        </p>
+      </td>
+    </tr>
+  </tbody>
+</table>
diff --git a/tools/build_defs/groovy/groovy.WORKSPACE b/tools/build_defs/groovy/groovy.WORKSPACE
index 8fce2532b1..ce196ba013 100644
--- a/tools/build_defs/groovy/groovy.WORKSPACE
+++ b/tools/build_defs/groovy/groovy.WORKSPACE
@@ -1,11 +1,27 @@
 new_http_archive(
-  name = "groovy",
+  name = "groovy-bin",
   url = "http://dl.bintray.com/groovy/maven/apache-groovy-binary-2.4.4.zip",
   sha256 = "a7cc1e5315a14ea38db1b2b9ce0792e35174161141a6a3e2ef49b7b2788c258c",
   build_file = "tools/build_defs/groovy/groovy.BUILD",
 )
 
-bind(
-  name = "groovy/groovyc",
-  actual = "@groovy//:groovyc",
+maven_jar(
+  name = "groovy",
+  group_id = "org.codehaus.groovy",
+  artifact_id = "groovy-all",
+  version = "2.3.7",
 )
+
+maven_jar(
+  name = "hamcrest",
+  group_id = "org.hamcrest",
+  artifact_id = "hamcrest-core",
+  version = "1.3",
+)
+
+maven_jar(
+  name = "junit",
+  group_id = "junit",
+  artifact_id = "junit",
+  version = "4.12",
+)
\ No newline at end of file
diff --git a/tools/build_defs/groovy/groovy.bzl b/tools/build_defs/groovy/groovy.bzl
index f435890e9d..3b65b8d707 100644
--- a/tools/build_defs/groovy/groovy.bzl
+++ b/tools/build_defs/groovy/groovy.bzl
@@ -29,9 +29,9 @@ def _groovy_jar_impl(ctx):
 
   # Compile all files in srcs with groovyc
   cmd = "rm -rf %s; mkdir -p %s\n" % (build_output, build_output)
-  cmd += "%s -cp %s -d %s %s\n" % (
+  cmd += "%s %s -d %s %s\n" % (
       ctx.file._groovyc.short_path,
-      ":".join([dep.path for dep in all_deps]),
+      "-cp " + ":".join([dep.path for dep in all_deps]) if len(all_deps) != 0 else "",
       build_output,
       " ".join([src.path for src in ctx.files.srcs]),
   )
@@ -70,7 +70,7 @@ _groovy_jar = rule(
             mandatory=False,
             allow_files=FileType([".jar"])),
         "_groovyc": attr.label(
-            default=Label("//external:groovy/groovyc"),
+            default=Label("@groovy-bin//:groovyc"),
             single_file=True),
         "_jar": attr.label(
             default=Label("//third_party/ijar:zipper"),
@@ -155,3 +155,57 @@ def groovy_binary(name, main_class, srcs=[], deps=[], **kwargs):
       runtime_deps = all_deps,
       **kwargs
   )
+
+def path_to_class(path):
+  if path.startswith("src/test/groovy/"):
+    return path[len("src/test/groovy/") : path.index(".groovy")].replace('/', '.')
+  elif path.startswith("src/test/java/"):
+    return path[len("src/test/java/") : path.index(".groovy")].replace('/', '.')
+  else:
+    fail("groovy_test sources must be under src/test/java or src/test/groovy")
+
+def groovy_test_impl(ctx):
+  # Extract all transitive dependencies
+  all_deps = set(ctx.files.deps + ctx.files._implicit_deps)
+  for this_dep in ctx.attr.deps:
+    if hasattr(this_dep, 'java'):
+      all_deps += this_dep.java.transitive_runtime_deps
+
+  # Infer a class name from each src file
+  classes = [path_to_class(src.path) for src in ctx.files.srcs]
+
+  # Write a file that executes JUnit on the inferred classes
+  cmd = "%s %s -cp %s org.junit.runner.JUnitCore %s\n" % (
+      ctx.executable._java.path,
+    " ".join(ctx.attr.jvm_flags),
+    ":".join([dep.short_path for dep in all_deps]),
+    " ".join(classes),
+  )
+  ctx.file_action(
+    output = ctx.outputs.executable,
+    content = cmd
+  )
+
+  # Return all dependencies needed to run the tests
+  return struct(
+    runfiles=ctx.runfiles(files=list(all_deps) + ctx.files._java),
+  )
+
+groovy_test = rule(
+  implementation = groovy_test_impl,
+  attrs = {
+    "srcs": attr.label_list(mandatory=True, allow_files=FileType([".groovy"])),
+    "deps": attr.label_list(allow_files=FileType([".jar"])),
+    "jvm_flags": attr.string_list(),
+    "_java": attr.label(
+      default=Label("@local-jdk//:java"),
+      executable=True,
+      single_file=True),
+    "_implicit_deps": attr.label_list(default=[
+      Label("@groovy//jar"),
+      Label("@hamcrest//jar"),
+      Label("@junit//jar"),
+    ]),
+  },
+  test = True,
+)