Add support for fish completion

Author: sayboras

.goreleaser.yml

@@ -92,6 +92,8 @@ brews:
       (bash_completion/"golangci-lint").write output
       output = Utils.popen_read("#{bin}/golangci-lint completion zsh")
       (zsh_completion/"_golangci-lint").write output
+      output = Utils.popen_read("#{bin}/golangci-lint completion fish")
+      (fish_completion/"eksctl.fish").write output
       prefix.install_metafiles
     test: |
       system "#{bin}/golangci-lint --version"

go.mod

@@ -45,7 +45,7 @@ require (
 	github.com/sirupsen/logrus v1.6.0
 	github.com/sonatard/noctx v0.0.1
 	github.com/sourcegraph/go-diff v0.6.0
-	github.com/spf13/cobra v1.0.0
+	github.com/spf13/cobra v1.0.1-0.20200710201246-675ae5f5a98c
 	github.com/spf13/pflag v1.0.5
 	github.com/spf13/viper v1.7.1
 	github.com/ssgreg/nlreturn/v2 v2.1.0

go.sum

@@ -344,8 +344,8 @@ github.com/spf13/afero v1.1.2 h1:m8/z1t7/fwjysjQRYbP0RD+bUIF/8tJwPdEZsI83ACI=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
 github.com/spf13/cast v1.3.0 h1:oget//CVOEoFewqQxwr0Ej5yjygnqGkvggSE/gB35Q8=
 github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
-github.com/spf13/cobra v1.0.0 h1:6m/oheQuQ13N9ks4hubMG6BnvwOeaJrqSPLahSnczz8=
-github.com/spf13/cobra v1.0.0/go.mod h1:/6GTrnGXV9HjY+aR4k0oJ5tcvakLuG6EuKReYlHNrgE=
+github.com/spf13/cobra v1.0.1-0.20200710201246-675ae5f5a98c h1:/dP/1GnfVIlWnB0YDImenSmneUCw3wjyq2RMgAG1e2o=
+github.com/spf13/cobra v1.0.1-0.20200710201246-675ae5f5a98c/go.mod h1:aeNIJzz/GSSVlS+gpCpQWZ83BKbsoW57mr90+YthtkQ=
 github.com/spf13/jwalterweatherman v1.0.0 h1:XHEdyB+EcvlqZamSM4ZOMGlc93t6AcsBEu9Gc1vn7yk=
 github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=

pkg/commands/completion.go

@@ -28,6 +28,13 @@ func (e *Executor) initCompletion() {
 		RunE:  e.executeZshCompletion,
 	}
 	completionCmd.AddCommand(zshCmd)
+
+	fishCmd := &cobra.Command{
+		Use:   "fish",
+		Short: "Output fish completion script",
+		RunE:  e.executeFishCompletion,
+	}
+	completionCmd.AddCommand(fishCmd)
 }
 
 func (e *Executor) executeBashCompletion(cmd *cobra.Command, args []string) error {
@@ -51,3 +58,12 @@ func (e *Executor) executeZshCompletion(cmd *cobra.Command, args []string) error
 
 	return nil
 }
+
+func (e *Executor) executeFishCompletion(cmd *cobra.Command, args []string) error {
+	err := cmd.Root().GenFishCompletion(os.Stdout, true)
+	if err != nil {
+		return errors.Wrap(err, "unable to generate fish completions: %v")
+	}
+
+	return nil
+}