[bazel] Generate pom.xml files for maven rules

java/client/src/org/openqa/selenium/BUILD.bazel

@@ -1,12 +1,13 @@
 load("//java:version.bzl", "SE_VERSION")
+load("//java:maven.bzl", "java_export")
 
 filegroup(
     name = "template-pom",
     srcs = ["pom.xml"],
     visibility = ["//visibility:public"],
 )
 
-java_library(
+java_export(
     name = "core",
     srcs = glob([
         "*.java",
@@ -16,9 +17,8 @@ java_library(
         "logging/**/*.java",
         "mobile/*.java",
     ]),
-    tags = [
-        "maven_coordinates=org.seleniumhq.selenium:selenium-api:%s" % SE_VERSION,
-    ],
+    maven_coordinates = "org.seleniumhq.selenium:selenium-api:%s" % SE_VERSION,
+    pom_template = ":template-pom",
     visibility = ["//visibility:public"],
     deps = [
         # Nothing from third party

java/client/src/org/openqa/selenium/firefox/BUILD.bazel

@@ -1,13 +1,13 @@
+load("//java:maven.bzl", "java_export")
 load("//java:version.bzl", "SE_VERSION")
 load("//:copy_file.bzl", "copy_file")
 
-java_library(
+java_export(
     name = "firefox",
     srcs = glob(["*.java"]),
     resources = [":prefs"],
-    tags = [
-        "maven_coordinates=org.seleniumhq.selenium:selenium-firefox-driver:%s" % SE_VERSION,
-    ],
+    maven_coordinates = "org.seleniumhq.selenium:selenium-firefox-driver:%s" % SE_VERSION,
+    pom_template = "//java/client/src/org/openqa/selenium:template-pom",
     visibility = ["//visibility:public"],
     deps = [
         "//java/client/src/org/openqa/selenium/json",

java/client/src/org/openqa/selenium/firefox/xpi/BUILD.bazel

@@ -1,17 +1,17 @@
+load("//java:maven.bzl", "java_export")
 load("//java:version.bzl", "SE_VERSION")
 load("//:copy_file.bzl", "copy_file")
 
-java_library(
+java_export(
     name = "xpi",
     srcs = glob(["*.java"]),
     resources = [
         ":amd64",
         ":i386",
         ":webdriver_xpi",
     ],
-    tags = [
-        "maven_coordinates=org.seleniumhq.selenium:selenium-firefox-xpi-driver:%s" % SE_VERSION,
-    ],
+    maven_coordinates = "org.seleniumhq.selenium:selenium-firefox-xpi-driver:%s" % SE_VERSION,
+    pom_template = "//java/client/src/org/openqa/selenium:template-pom",
     visibility = ["//visibility:public"],
     deps = [
         "//java/client/src/org/openqa/selenium:core",

java/client/src/org/openqa/selenium/pom.xml

@@ -2,18 +2,27 @@
 <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <modelVersion>4.0.0</modelVersion>
-  <groupId>org.seleniumhq.selenium</groupId>
-  <artifactId>empty</artifactId>
-  <version>unknown</version>
+
+  <groupId>{groupId}</groupId>
+  <artifactId>{artifactId}</artifactId>
+  <version>{version}</version>
   <description>Selenium automates browsers. That's it! What you do with that power is entirely up to you.</description>
   <url>http://www.seleniumhq.org/</url>
+
   <licenses>
     <license>
       <name>The Apache Software License, Version 2.0</name>
       <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
       <distribution>repo</distribution>
     </license>
   </licenses>
+
+  <scm>
+    <url>https://github.com/SeleniumHQ/selenium/</url>
+    <connection>scm:git:https://github.com/SeleniumHQ/selenium.git</connection>
+    <developerConnection>scm:git:git@github.com:SeleniumHQ/selenium.git</developerConnection>
+  </scm>
+
   <developers>
     <developer>
       <id>simon.m.stewart</id>
@@ -86,9 +95,8 @@
       </roles>
     </developer>
   </developers>
-  <scm>
-    <connection>scm:git:git@github.com:SeleniumHQ/selenium.git</connection>
-    <developerConnection>scm:git:git@github.com:SeleniumHQ/selenium.git</developerConnection>
-    <url>https://github.com/SeleniumHQ/selenium/</url>
-  </scm>
+
+  <dependencies>
+{dependencies}
+  </dependencies>
 </project>

java/client/src/org/openqa/selenium/remote/BUILD.bazel

@@ -1,4 +1,5 @@
 load("//java:version.bzl", "SE_VERSION")
+load("//java:maven.bzl", "java_export")
 
 java_library(
     name = "api",
@@ -43,7 +44,7 @@ java_library(
     srcs = ["HttpSessionId.java"],
 )
 
-java_library(
+java_export(
     name = "remote",
     srcs = [
         "AddRotatable.java",
@@ -57,9 +58,8 @@ java_library(
         "html5/AddWebStorage.java",
         "mobile/AddNetworkConnection.java",
     ],
-    tags = [
-        "maven_coordinates=org.seleniumhq.selenium:selenium-remote-driver:%s" % SE_VERSION,
-    ],
+    maven_coordinates = "org.seleniumhq.selenium:selenium-remote-driver:%s" % SE_VERSION,
+    pom_template = "//java/client/src/org/openqa/selenium:template-pom",
     visibility = ["//visibility:public"],
     exports = [
         ":api",

java/maven.bzl

@@ -33,12 +33,22 @@ def _has_maven_deps_impl(target, ctx):
     all_infos = [dep[MavenInfo] for dep in all_deps if MavenInfo in dep]
 
     maven_deps = depset([], transitive = [info.transitive_maven_deps for info in all_infos])
-    transitive_maven_deps = depset(coordinates, transitive = [info.transitive_maven_deps for info in all_infos])
+
+    # Because of the way that maven works, if a rule has maven coordinates,
+    # it's enough to set set the transitive deps to just be the rule for
+    # anything that depends upon it. Otherwise, gather them up, and carry on
+    # as if nothing really mattered.
+
+    if len(coordinates) > 0:
+      transitive_maven_deps = depset(coordinates)
+    else:
+      transitive_maven_deps = depset(coordinates, transitive = [info.transitive_maven_deps for info in all_infos])
     artifact_jars = depset(java_info.runtime_output_jars, transitive = [info.artifact_jars for info in all_infos if not info.coordinates])
     source_jars = depset(java_info.source_jars, transitive = [info.source_jars for info in all_infos if not info.coordinates])
 
     infos = []
     coordinate = coordinates[0] if len(coordinates) > 0 else None
+
     info = MavenInfo(
         coordinates = coordinate,
         maven_deps = maven_deps,
@@ -119,3 +129,128 @@ maven_jars = rule(
           allow_files = True),
     },
 )
+
+_PLAIN_DEP = """    <dependency>
+      <groupId>{0}</groupId>
+      <artifactId>{1}</artifactId>
+      <version>{2}</version>
+    </dependency>"""
+
+_TYPED_DEP = """    <dependency>
+      <groupId>{0}</groupId>
+      <artifactId>{1}</artifactId>
+      <version>{2}</version>
+      <type>{3}</type>
+    </dependency>"""
+
+
+def explode_coordinates(coords):
+    """Takes a maven coordinate and explodes it into a tuple of
+    (groupId, artifactId, version, type)
+    """
+    parts = coords.split(":")
+    if len(parts) == 3:
+        return (parts[0], parts[1], parts[2], "jar")
+    if len(parts) == 4:
+        # Assume a buildr coordinate: groupId:artifactId:type:version
+        return (parts[0], parts[1], parts[3], parts[2])
+
+    fail("Unparsed: %s" % coords)
+
+
+def _pom_file_impl(ctx):
+    # Ensure the target has coordinates
+    if not ctx.attr.target[MavenInfo].coordinates:
+        fail("pom_file target must have maven coordinates.")
+
+    info = ctx.attr.target[MavenInfo]
+
+    # Separate out the various parts of the
+
+    coordinates = explode_coordinates(info.coordinates)
+    substitutions = {
+        "{groupId}": coordinates[0],
+        "{artifactId}": coordinates[1],
+        "{version}": coordinates[2],
+        "{type}": coordinates[3],
+    }
+
+    deps = []
+    for dep in sorted(info.maven_deps.to_list()):
+        exploded = explode_coordinates(dep)
+        if (exploded[3] == "jar"):
+            template = _PLAIN_DEP
+        else:
+            template = _TYPED_DEP
+        deps.append(template.format(*exploded))
+    substitutions.update({"{dependencies}": "\n".join(deps)})
+
+    out = ctx.actions.declare_file("%s.xml" % ctx.attr.name)
+    ctx.actions.expand_template(
+        template = ctx.file.template,
+        output = out,
+        substitutions = substitutions,
+    )
+
+    return [
+        DefaultInfo(files = depset([out]))
+    ]
+
+pom_file = rule(
+    _pom_file_impl,
+    attrs = {
+        "target": attr.label(
+            aspects = [_has_maven_deps],
+            providers = [JavaInfo, MavenInfo]),
+        "template": attr.label(
+            allow_single_file = True,
+        ),
+        "_zip": attr.label(
+            executable = True,
+            cfg = "host",
+            default = "@bazel_tools//tools/zip:zipper",
+            allow_files = True ),
+    },
+)
+
+def java_export(
+        name,
+        maven_coordinates=None,
+        pom_template=None,
+        tags=[],
+        srcs=None,
+        deps=None,
+        exports=None,
+        resources=None,
+        runtime_deps=None,
+        neverlink=False,
+        visibility=None):
+
+    actual_tags = tags
+    if maven_coordinates:
+        actual_tags = tags + ["%s%s" % (_PREFIX, maven_coordinates)]
+        if not pom_template:
+            fail("java_export requires pom_template to be set if coordinates given: %s" % maven_coordinates)
+
+    native.java_library(
+        name = name,
+        srcs = srcs,
+        resources = resources,
+        deps = deps,
+        exports = exports,
+        runtime_deps = runtime_deps,
+        tags = actual_tags,
+        visibility = visibility)
+
+    pom_file(
+        name = "%s-pom" % name,
+        target = ":%s" % name,
+        template = pom_template,
+        visibility = visibility,
+    )
+
+    maven_jars(
+        name = "%s-maven" % name,
+        targets = [":%s" % name],
+        visibility = visibility,
+    )