language/go: merge new Go naming convention to master (#863)

With this change, Gazelle supports multiple naming conventions for Go targets.
In new projects, new targets will be named after their import paths by default.
Existing projects can continue to use their current naming convention (which
will be detected automatically in most cases), or they may migrate by adding
this directive to their root build file, then running Gazelle.

    # gazelle:go_naming_convention import

go_repository uses the import_alias convention by default, which generates
targets using the import convention and aliases using the go_default_library
convention.

Thanks to @tomlu for implementing nearly all of this!

Fixes #5

BUILD.bazel

@@ -6,6 +6,7 @@ load("//:def.bzl", "gazelle", "gazelle_binary")
 # gazelle:exclude third_party
 # gazelle:exclude .bazelci
 # gazelle:exclude .github
+# gazelle:go_naming_convention import_alias
 gazelle(
     name = "gazelle",
     command = "fix",
@@ -15,9 +16,9 @@ gazelle(
 gazelle_binary(
     name = "gazelle_local",
     languages = [
-        "//language/proto:go_default_library",
-        "//language/go:go_default_library",
-        "//internal/language/test_filegroup:go_default_library",
+        "//language/proto",
+        "//language/go",
+        "//internal/language/test_filegroup",
     ],
 )
 

README.rst

@@ -332,6 +332,17 @@ The following flags are accepted:
 | See `Predefined plugins`_ for available options; commonly used options include                        |
 | ``@io_bazel_rules_go//proto:gofast_grpc`` and ``@io_bazel_rules_go//proto:gogofaster_grpc``.          |
 +--------------------------------------------------------------+----------------------------------------+
+| :flag:`-go_naming_convention`                                |                                        |
++--------------------------------------------------------------+----------------------------------------+
+| Controls the names of generated Go targets. Equivalent to the                                         |
+| ``# gazelle:go_naming_convention`` directive.                                                         |
++--------------------------------------------------------------+----------------------------------------+
+| :flag:`-go_naming_convention_extern`                         |                                        |
++--------------------------------------------------------------+----------------------------------------+
+| Controls the default naming convention used when resolving libraries in                               |
+| external repositories with unknown naming conventions. Equivalent to the                              |
+| ``# gazelle:go_naming_convention_extern`` directive.                                                  |
++--------------------------------------------------------------+----------------------------------------+
 | :flag:`-go_prefix example.com/repo`                          |                                        |
 +--------------------------------------------------------------+----------------------------------------+
 | A prefix of import paths for libraries in the repository that corresponds to                          |
@@ -576,6 +587,30 @@ The following directives are recognized:
 | ``@io_bazel_rules_go//proto:gofast_grpc`` and                                              |
 | ``@io_bazel_rules_go//proto:gogofaster_grpc``.                                             |
 +---------------------------------------------------+----------------------------------------+
+| :direc:`# gazelle:go_naming_convention`           | n/a                                    |
++---------------------------------------------------+----------------------------------------+
+| Controls the names of generated Go targets. By default, library targets are named          |
+| ``go_default_library`` and test targets ``go_default_test``.                               |
+|                                                                                            |
+| Valid values are:                                                                          |
+|                                                                                            |
+| * ``go_default_library``: Library targets are named ``go_default_library``, test targets   |
+|   are named ``go_default_test``.                                                           |
+| * ``import``: Library and test targets are named after the last segment of their import    |
+|   path.                                                                                    |
+|   For example, ``example.repo/foo`` is named ``foo``, and the test target is ``foo_test``. |
+|   Major version suffixes like ``/v2`` are dropped.                                         |
+|   For a main package with a binary ``foobin``, the names are instead ``foobin_lib`` and    |
+|   ``foobin_test``.                                                                         |
+| * ``import_alias``: Same as ``import``, but an ``alias`` target is generated named         |
+|   ``go_default_library`` to ensure backwards compatibility.                                |
++---------------------------------------------------+----------------------------------------+
+| :direc:`# gazelle:go_naming_convention_extern`    | n/a                                    |
++---------------------------------------------------+----------------------------------------+
+| Controls the default naming convention used when resolving libraries in                    |
+| external repositories with unknown naming conventions. Accepts the same values             |
+| as ``go_naming_convention``.                                                               |
++---------------------------------------------------+----------------------------------------+
 | :direc:`# gazelle:go_proto_compilers`             | ``@io_bazel_rules_go//proto:go_proto`` |
 +---------------------------------------------------+----------------------------------------+
 | The protocol buffers compiler(s) to use for building go bindings.                          |

WORKSPACE

@@ -22,3 +22,13 @@ go_register_toolchains(nogo = "@bazel_gazelle//:nogo")
 load("//:deps.bzl", "gazelle_dependencies")
 
 gazelle_dependencies()
+
+# gazelle:repository go_repository name=org_golang_x_sync importpath=golang.org/x/sync
+# gazelle:repository go_repository name=org_golang_x_sys importpath=golang.org/x/sys
+# gazelle:repository go_repository name=org_golang_x_xerrors importpath=golang.org/x/xerrors
+# gazelle:repository go_repository name=com_github_bazelbuild_buildtools importpath=github.com/bazelbuild/buildtools build_naming_convention=go_default_library
+# gazelle:repository go_repository name=com_github_fsnotify_fsnotify importpath=github.com/fsnotify/fsnotify
+# gazelle:repository go_repository name=com_github_pelletier_go_toml importpath=github.com/pelletier/go-toml
+# gazelle:repository go_repository name=com_github_pmezard_go_difflib importpath=github.com/pmezard/go-difflib
+# gazelle:repository go_repository name=com_github_bmatcuk_doublestar importpath=github.com/bmatcuk/doublestar
+# gazelle:repository go_repository name=com_github_google_go_cmp importpath=github.com/google/go-cmp

cmd/autogazelle/BUILD.bazel

@@ -1,7 +1,7 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 
 go_library(
-    name = "go_default_library",
+    name = "autogazelle_lib",
     srcs = [
         "autogazelle.go",
         "client_unix.go",
@@ -11,42 +11,42 @@ go_library(
     visibility = ["//visibility:private"],
     deps = select({
         "@io_bazel_rules_go//go/platform:android": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:darwin": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:dragonfly": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:freebsd": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:ios": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:linux": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:nacl": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:netbsd": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:openbsd": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "@io_bazel_rules_go//go/platform:solaris": [
-            "@com_github_fsnotify_fsnotify//:go_default_library",
+            "@com_github_fsnotify_fsnotify//:fsnotify",
         ],
         "//conditions:default": [],
     }),
 )
 
 go_binary(
     name = "autogazelle",
-    embed = [":go_default_library"],
+    embed = [":autogazelle_lib"],
     visibility = ["//visibility:public"],
 )
 

cmd/fetch_repo/BUILD.bazel

@@ -1,7 +1,7 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library", "go_test")
 
 go_library(
-    name = "go_default_library",
+    name = "fetch_repo_lib",
     srcs = [
         "fetch_repo.go",
         "module.go",
@@ -14,14 +14,14 @@ go_library(
 
 go_binary(
     name = "fetch_repo",
-    embed = [":go_default_library"],
+    embed = [":fetch_repo_lib"],
     visibility = ["//visibility:public"],
 )
 
 go_test(
-    name = "go_default_test",
+    name = "fetch_repo_test",
     srcs = ["fetch_repo_test.go"],
-    embed = [":go_default_library"],
+    embed = [":fetch_repo_lib"],
     deps = ["@org_golang_x_tools//go/vcs:go_default_library"],
 )
 

cmd/gazelle/BUILD.bazel

@@ -23,7 +23,7 @@ gazelle_binary(
 )
 
 go_library(
-    name = "go_default_library",
+    name = "gazelle_lib",
     # keep
     srcs = [
         "diff.go",
@@ -38,25 +38,25 @@ go_library(
     tags = ["manual"],
     visibility = ["//visibility:public"],
     deps = [
-        "//config:go_default_library",
-        "//flag:go_default_library",
-        "//internal/wspace:go_default_library",
-        "//label:go_default_library",
-        "//language:go_default_library",
-        "//language/go:go_default_library",
-        "//language/proto:go_default_library",
-        "//merger:go_default_library",
-        "//repo:go_default_library",
-        "//resolve:go_default_library",
-        "//rule:go_default_library",
-        "//walk:go_default_library",
+        "//config",
+        "//flag",
+        "//internal/wspace",
+        "//label",
+        "//language",
+        "//language/go",
+        "//language/proto",
+        "//merger",
+        "//repo",
+        "//resolve",
+        "//rule",
+        "//walk",
         "@com_github_bazelbuild_buildtools//build:go_default_library",
-        "@com_github_pmezard_go_difflib//difflib:go_default_library",
+        "@com_github_pmezard_go_difflib//difflib",
     ],
 )
 
 go_test(
-    name = "go_default_test",
+    name = "gazelle_test",
     size = "small",
     srcs = [
         "diff_test.go",
@@ -66,11 +66,11 @@ go_test(
     ],
     args = ["-go_sdk=go_sdk"],
     data = ["@go_sdk//:files"],
-    embed = [":go_default_library"],
+    embed = [":gazelle_lib"],
     deps = [
-        "//config:go_default_library",
-        "//internal/wspace:go_default_library",
-        "//testtools:go_default_library",
+        "//config",
+        "//internal/wspace",
+        "//testtools",
         "@io_bazel_rules_go//go/tools/bazel:go_default_library",
     ],
 )

cmd/gazelle/diff_test.go

@@ -55,7 +55,7 @@ func TestDiffExisting(t *testing.T) {
  # gazelle:prefix example.com/hello
  
 +go_library(
-+    name = "go_default_library",
++    name = "hello",
 +    srcs = ["hello.go"],
 +    importpath = "example.com/hello",
 +    visibility = ["//visibility:public"],
@@ -91,7 +91,7 @@ func TestDiffNew(t *testing.T) {
 +load("@io_bazel_rules_go//go:def.bzl", "go_library")
 +
 +go_library(
-+    name = "go_default_library",
++    name = "hello",
 +    srcs = ["hello.go"],
 +    importpath = "example.com/hello",
 +    visibility = ["//visibility:public"],
@@ -138,7 +138,7 @@ func TestDiffReadWriteDir(t *testing.T) {
  # gazelle:prefix example.com/hello
 +
 +go_library(
-+    name = "go_default_library",
++    name = "hello",
 +    srcs = ["hello.go"],
 +    importpath = "example.com/hello",
 +    visibility = ["//visibility:public"],

cmd/gazelle/fix_test.go

@@ -257,13 +257,13 @@ load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 
 go_binary(
     name = "hello",
-    embed = [":go_default_library"],
+    embed = [":repo_lib"],
     pure = "on",
     visibility = ["//visibility:public"],
 )
 
 go_library(
-    name = "go_default_library",
+    name = "repo_lib",
     srcs = ["hello.go"],
     importpath = "example.com/repo",
     visibility = ["//visibility:private"],
@@ -291,15 +291,15 @@ load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 # src build file
 
 go_library(
-    name = "go_default_library",
+    name = "repo_lib",
     srcs = ["hello.go"],
     importpath = "example.com/repo",
     visibility = ["//visibility:private"],
 )
 
 go_binary(
     name = "repo",
-    embed = [":go_default_library"],
+    embed = [":repo_lib"],
     visibility = ["//visibility:public"],
 )
 `,
@@ -324,13 +324,13 @@ load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
 
 go_binary(
     name = "hello",
-    embed = [":go_default_library"],
+    embed = [":repo_lib"],
     pure = "on",
     visibility = ["//visibility:public"],
 )
 
 go_library(
-    name = "go_default_library",
+    name = "repo_lib",
     srcs = ["hello.go"],
     importpath = "example.com/repo",
     visibility = ["//visibility:private"],