Fix map_kind with empty rules (#1441)

* fix: language/go: fileContainsGoBinary() doesn't interprete correctly KindMap

With this directive `# gazelle:map_kind OLD NEW NEW_LOAD`,
c.KindMap should be equal:

  "OLD": {
    FromKind: "OLD",
    KindName: "NEW",
    KindLoad: "NEW_LOAD",
  }

`fileContainsGoBinary()` should search directly the mapping
for the `go_binary` kind rule.

Issue #1440

* fix: map_kind should also be applied on empty rules

If `map_kind` is not applied on empty rules returned
by GenerateRules(), all mapped rules can't be removed
from the BUILD file.

Close #1440

cmd/gazelle/fix-update.go

@@ -375,6 +375,14 @@ func runFixUpdate(wd string, cmd command, args []string) (err error) {
 				r.SetKind(repl.KindName)
 			}
 		}
+		for _, r := range empty {
+			if repl, ok := c.KindMap[r.Kind()]; ok {
+				mappedKindInfo[repl.KindName] = kinds[r.Kind()]
+				mappedKinds = append(mappedKinds, repl)
+				mrslv.MappedKind(rel, repl)
+				r.SetKind(repl.KindName)
+			}
+		}
 
 		// Insert or merge rules into the build file.
 		if f == nil {

cmd/gazelle/integration_test.go

@@ -1970,6 +1970,47 @@ go_library(
 			Path:    "enabled/existing_rules/unmapped/unmapped_lib.go",
 			Content: `package unmapped`,
 		},
+		{
+			Path: "enabled/existing_rules/clean/BUILD.bazel",
+			Content: `load("//tools/go:def.bzl", "my_go_library")
+
+# gazelle:go_naming_convention import
+# gazelle:map_kind go_library my_go_library //tools/go:def.bzl
+
+my_go_library(
+    name = "clean",
+    srcs = [
+        "foo.go",
+        "bar.go",
+        "buz.go",
+    ],
+    importpath = "example.com/mapkind/enabled/existing_rules/clean",
+    visibility = ["//visibility:private"],
+)
+`,
+		},
+		{
+			Path: "enabled/existing_rules/clean_binary/BUILD.bazel",
+			Content: `load("//tools/go:def.bzl", "my_go_binary", "my_go_library")
+
+# gazelle:go_naming_convention import
+# gazelle:map_kind go_binary my_go_binary //tools/go:def.bzl
+# gazelle:map_kind go_library my_go_library //tools/go:def.bzl
+
+my_go_library(
+    name = "clean_binary_lib",
+    srcs = ["main.go"],
+    importpath = "example.com/mapkind/enabled/existing_rules/clean_binary",
+    visibility = ["//visibility:private"],
+)
+
+my_go_binary(
+    name = "clean_binary",
+    embed = [":clean_binary_lib"],
+    visibility = ["//visibility:public"],
+)
+`,
+		},
 		{
 			Path:    "enabled/existing_rules/nobuild/nobuild_lib.go",
 			Content: `package nobuild`,
@@ -2124,6 +2165,21 @@ my_library(
     importpath = "example.com/mapkind/enabled/existing_rules/unmapped",
     visibility = ["//visibility:public"],
 )
+`,
+		},
+		{
+			Path: "enabled/existing_rules/clean/BUILD.bazel",
+			Content: `
+# gazelle:go_naming_convention import
+# gazelle:map_kind go_library my_go_library //tools/go:def.bzl
+`,
+		},
+		{
+			Path: "enabled/existing_rules/clean_binary/BUILD.bazel",
+			Content: `
+# gazelle:go_naming_convention import
+# gazelle:map_kind go_binary my_go_binary //tools/go:def.bzl
+# gazelle:map_kind go_library my_go_library //tools/go:def.bzl
 `,
 		},
 		{

language/go/fix.go

@@ -117,12 +117,15 @@ func fileContainsGoBinary(c *config.Config, f *rule.File) bool {
 	}
 	for _, r := range f.Rules {
 		kind := r.Kind()
-		if mappedKind, ok := c.KindMap[kind]; ok {
-			kind = mappedKind.KindName
-		}
 		if kind == "go_binary" {
 			return true
 		}
+
+		if mappedKind, ok := c.KindMap["go_binary"]; ok {
+			if mappedKind.KindName == kind {
+				return true
+			}
+		}
 	}
 	return false
 }