Untangle resolvers

private/rules/coursier.bzl

@@ -721,6 +721,13 @@ def generate_pin_target(repository_ctx, unpinned_pin_target):
         else:
             lock_file_location = "/".join([package_path, file_name])  # e.g. path/to/some.json
 
+        if repository_ctx.attr.resolver == "maven":
+            resolver_target = Label("//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/maven:MavenMain")
+        elif repository_ctx.attr.resolver == "gradle":
+            resolver_target = Label("//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/gradle:GradleMain")
+        else:
+            fail("Unknown resolver")
+
         return _IN_REPO_PIN.format(
             boms = repr(repository_ctx.attr.boms),
             artifacts = repr(repository_ctx.attr.artifacts),
@@ -730,7 +737,7 @@ def generate_pin_target(repository_ctx, unpinned_pin_target):
             fetch_sources = repr(repository_ctx.attr.fetch_sources),
             fetch_javadocs = repr(repository_ctx.attr.fetch_javadoc),
             lock_file = repr(lock_file_location),
-            resolver = repr(repository_ctx.attr.resolver),
+            resolver = repr(str(resolver_target)),
         )
 
 def infer_artifact_path_from_primary_and_repos(primary_url, repository_urls):

private/rules/pin_dependencies.bzl

@@ -15,7 +15,7 @@ load("//private/rules:coursier.bzl", "compute_dependency_inputs_signature")
 
 _TEMPLATE = """#!/usr/bin/env bash
 
-{resolver_cmd} --jvm_flags={jvm_flags} --argsfile {config} --resolver {resolver} --input_hash '{input_hash}' --output {output}
+{resolver_cmd} --jvm_flags={jvm_flags} --argsfile {config} --input_hash '{input_hash}' --output {output}
 """
 
 def _stringify_exclusions(exclusions):
@@ -76,8 +76,7 @@ def _pin_dependencies_impl(ctx):
         _TEMPLATE.format(
             config = config_file.short_path,
             input_hash = input_hash[0],
-            resolver_cmd = ctx.executable._resolver.short_path,
-            resolver = ctx.attr.resolver,
+            resolver_cmd = ctx.executable.resolver.short_path,
             output = "$BUILD_WORKSPACE_DIRECTORY/" + ctx.attr.lock_file,
             jvm_flags = ctx.attr.jvm_flags,
         ),
@@ -88,19 +87,14 @@ def _pin_dependencies_impl(ctx):
         DefaultInfo(
             executable = script,
             files = depset([script, config_file]),
-            runfiles = ctx.runfiles(files = [script, config_file]).merge(ctx.attr._resolver[DefaultInfo].default_runfiles),
+            runfiles = ctx.runfiles(files = [script, config_file]).merge(ctx.attr.resolver[DefaultInfo].default_runfiles),
         ),
     ]
 
 pin_dependencies = rule(
     _pin_dependencies_impl,
     executable = True,
     attrs = {
-        "resolver": attr.string(
-            doc = "The resolver to use",
-            values = ["gradle", "maven"],
-            default = "maven",
-        ),
         "artifacts": attr.string_list(
             doc = "List of JSON blobs generated by parse_artifact_spec_list",
         ),
@@ -122,7 +116,7 @@ pin_dependencies = rule(
         "jvm_flags": attr.string(
             doc = "JVM flags to pass to resolver",
         ),
-        "_resolver": attr.label(
+        "resolver": attr.label(
             executable = True,
             cfg = "exec",
             default = "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/cmd:Resolver",

private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/cmd/Main.java → private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/cmd/AbstractMain.java

@@ -28,6 +28,7 @@
 import com.github.bazelbuild.rules_jvm_external.resolver.events.EventListener;
 import com.github.bazelbuild.rules_jvm_external.resolver.events.PhaseEvent;
 import com.github.bazelbuild.rules_jvm_external.resolver.lockfile.V2LockFile;
+import com.github.bazelbuild.rules_jvm_external.resolver.netrc.Netrc;
 import com.github.bazelbuild.rules_jvm_external.resolver.remote.DownloadResult;
 import com.github.bazelbuild.rules_jvm_external.resolver.remote.Downloader;
 import com.github.bazelbuild.rules_jvm_external.resolver.remote.HttpDownloader;
@@ -56,20 +57,20 @@
 import java.util.concurrent.Executors;
 import java.util.function.Supplier;
 
-public class Main {
+public abstract class AbstractMain {
 
-  public static void main(String[] args) throws IOException {
+  public void doMain(String[] args) {
     Set<DependencyInfo> infos;
     try (EventListener listener = HttpDownloader.defaultEventListener()) {
       ResolverConfig config = new ResolverConfig(listener, args);
 
       ResolutionRequest request = config.getResolutionRequest();
 
-      Resolver resolver = config.getResolver();
+      Resolver resolver = getResolver(config.getNetrc(), config.getMaxThreads(), listener);
 
       ResolutionResult resolutionResult = resolver.resolve(request);
 
-      infos = fulfillDependencyInfos(listener, config, resolutionResult.getResolution());
+      infos = fulfillDependencyInfos(resolver, listener, config, resolutionResult.getResolution());
 
       writeLockFile(listener, config, request, infos, resolutionResult.getConflicts());
 
@@ -80,8 +81,13 @@ public static void main(String[] args) throws IOException {
     }
   }
 
+  public abstract Resolver getResolver(Netrc netrc, int maxThreads, EventListener listener);
+
   private static Set<DependencyInfo> fulfillDependencyInfos(
-      EventListener listener, ResolverConfig config, Graph<Coordinates> resolved) {
+      Resolver resolver,
+      EventListener listener,
+      ResolverConfig config,
+      Graph<Coordinates> resolved) {
     listener.onEvent(new PhaseEvent("Downloading dependencies"));
 
     ResolutionRequest request = config.getResolutionRequest();
@@ -94,7 +100,7 @@ private static Set<DependencyInfo> fulfillDependencyInfos(
     Downloader downloader =
         new Downloader(
             config.getNetrc(),
-            request.getLocalCache(config.getResolver().getName()),
+            request.getLocalCache(resolver.getName()),
             request.getRepositories(),
             listener,
             cacheResults);

private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/cmd/BUILD

@@ -1,4 +1,4 @@
-load("@rules_java//java:defs.bzl", "java_binary", "java_library")
+load("@rules_java//java:defs.bzl", "java_library")
 load("@rules_jvm_external//:defs.bzl", "artifact")
 
 java_library(
@@ -12,9 +12,7 @@ java_library(
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/jar:IndexJar-lib",
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver",
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/events",
-        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/gradle",
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/lockfile",
-        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/maven",
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/netrc",
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/remote",
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/ui",
@@ -28,14 +26,3 @@ java_library(
         ),
     ],
 )
-
-java_binary(
-    name = "Resolver",
-    main_class = "com.github.bazelbuild.rules_jvm_external.resolver.cmd.Main",
-    visibility = [
-        "//visibility:public",
-    ],
-    runtime_deps = [
-        ":cmd",
-    ],
-)

private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/cmd/ResolverConfig.java

@@ -16,11 +16,8 @@
 
 import com.github.bazelbuild.rules_jvm_external.Coordinates;
 import com.github.bazelbuild.rules_jvm_external.resolver.ResolutionRequest;
-import com.github.bazelbuild.rules_jvm_external.resolver.Resolver;
 import com.github.bazelbuild.rules_jvm_external.resolver.events.EventListener;
 import com.github.bazelbuild.rules_jvm_external.resolver.events.PhaseEvent;
-import com.github.bazelbuild.rules_jvm_external.resolver.gradle.GradleResolver;
-import com.github.bazelbuild.rules_jvm_external.resolver.maven.MavenResolver;
 import com.github.bazelbuild.rules_jvm_external.resolver.netrc.Netrc;
 import com.google.gson.Gson;
 import com.google.gson.reflect.TypeToken;
@@ -37,7 +34,6 @@ public class ResolverConfig {
   public static final int DEFAULT_MAX_THREADS =
       Math.min(5, Runtime.getRuntime().availableProcessors());
   private final ResolutionRequest request;
-  private final Resolver resolver;
   private final boolean fetchSources;
   private final boolean fetchJavadoc;
   private final Netrc netrc;
@@ -50,7 +46,6 @@ public ResolverConfig(EventListener listener, String... args) throws IOException
     this.netrc = Netrc.fromUserHome();
 
     ResolutionRequest request = new ResolutionRequest();
-    String chosenResolver = "maven";
     boolean fetchSources = false;
     boolean fetchJavadoc = false;
     int maxThreads = DEFAULT_MAX_THREADS;
@@ -99,22 +94,6 @@ public ResolverConfig(EventListener listener, String... args) throws IOException
           }
           break;
 
-        case "--resolver":
-          i++;
-          switch (args[i]) {
-            case "gradle":
-              chosenResolver = "gradle";
-              break;
-
-            case "maven":
-              chosenResolver = "maven";
-              break;
-
-            default:
-              throw new IllegalArgumentException("Resolver must be one of `maven` or `gradle`");
-          }
-          break;
-
         case "--sources":
           fetchSources = true;
           break;
@@ -153,10 +132,6 @@ public ResolverConfig(EventListener listener, String... args) throws IOException
 
       config.getRepositories().forEach(request::addRepository);
 
-      if (config.getResolver() != null) {
-        chosenResolver = config.getResolver();
-      }
-
       config.getGlobalExclusions().forEach(request::exclude);
 
       config
@@ -208,24 +183,12 @@ public ResolverConfig(EventListener listener, String... args) throws IOException
     this.inputHash = inputHash;
     this.maxThreads = maxThreads;
     this.output = output;
-
-    if (chosenResolver.equals("maven")) {
-      this.resolver = new MavenResolver(netrc, maxThreads, listener);
-    } else if (chosenResolver.equals("gradle")) {
-      this.resolver = new GradleResolver(netrc, maxThreads, listener);
-    } else {
-      throw new RuntimeException("Unknown resolver: " + chosenResolver);
-    }
   }
 
   public ResolutionRequest getResolutionRequest() {
     return request;
   }
 
-  public Resolver getResolver() {
-    return resolver;
-  }
-
   public boolean isFetchSources() {
     return fetchSources;
   }

private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/gradle/BUILD.bazel

@@ -3,7 +3,10 @@ load("@rules_jvm_external//:defs.bzl", "artifact")
 
 java_library(
     name = "gradle",
-    srcs = glob(["*.java"]),
+    srcs = glob(
+        ["*.java"],
+        exclude = ["GradleMain.java"],
+    ),
     data = [
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/gradle/data:gradle_build_templates",
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/gradle/plugin:plugin-single-jar",
@@ -41,3 +44,19 @@ java_library(
         "@gradle",
     ],
 )
+
+java_binary(
+    name = "GradleMain",
+    srcs = [
+        "GradleMain.java",
+    ],
+    main_class = "com.github.bazelbuild.rules_jvm_external.resolver.gradle.GradleMain",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":gradle",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/cmd",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/events",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/netrc",
+    ],
+)

private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/gradle/GradleMain.java

@@ -0,0 +1,18 @@
+package com.github.bazelbuild.rules_jvm_external.resolver.gradle;
+
+import com.github.bazelbuild.rules_jvm_external.resolver.Resolver;
+import com.github.bazelbuild.rules_jvm_external.resolver.cmd.AbstractMain;
+import com.github.bazelbuild.rules_jvm_external.resolver.events.EventListener;
+import com.github.bazelbuild.rules_jvm_external.resolver.netrc.Netrc;
+
+public class GradleMain extends AbstractMain {
+
+  public static void main(String[] args) {
+    new GradleMain().doMain(args);
+  }
+
+  @Override
+  public Resolver getResolver(Netrc netrc, int maxThreads, EventListener listener) {
+    return new GradleResolver(netrc, maxThreads, listener);
+  }
+}

private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/maven/BUILD

@@ -3,7 +3,10 @@ load("@rules_jvm_external//:defs.bzl", "artifact")
 
 java_library(
     name = "maven",
-    srcs = glob(["*.java"]),
+    srcs = glob(
+        ["*.java"],
+        exclude = ["MavenMain.java"],
+    ),
     visibility = [
         "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver:__subpackages__",
         "//tests/com/github/bazelbuild/rules_jvm_external:__subpackages__",
@@ -91,3 +94,19 @@ java_library(
         ),
     ],
 )
+
+java_binary(
+    name = "MavenMain",
+    srcs = [
+        "MavenMain.java",
+    ],
+    main_class = "com.github.bazelbuild.rules_jvm_external.resolver.maven.MavenMain",
+    visibility = ["//visibility:public"],
+    deps = [
+        ":maven",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/cmd",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/events",
+        "//private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/netrc",
+    ],
+)

private/tools/java/com/github/bazelbuild/rules_jvm_external/resolver/maven/MavenMain.java

@@ -0,0 +1,18 @@
+package com.github.bazelbuild.rules_jvm_external.resolver.maven;
+
+import com.github.bazelbuild.rules_jvm_external.resolver.Resolver;
+import com.github.bazelbuild.rules_jvm_external.resolver.cmd.AbstractMain;
+import com.github.bazelbuild.rules_jvm_external.resolver.events.EventListener;
+import com.github.bazelbuild.rules_jvm_external.resolver.netrc.Netrc;
+
+public class MavenMain extends AbstractMain {
+
+  public static void main(String[] args) {
+    new MavenMain().doMain(args);
+  }
+
+  @Override
+  public Resolver getResolver(Netrc netrc, int maxThreads, EventListener listener) {
+    return new MavenResolver(netrc, maxThreads, listener);
+  }
+}