chore: modernize CI and document deprecated ioutil usages

.github/workflows/ci.yml

@@ -2,6 +2,9 @@ name: ci
 
 on: [push, pull_request]
 
+permissions:
+  contents: read
+
 jobs:
   build:
     runs-on: ubuntu-latest
@@ -10,6 +13,10 @@ jobs:
       matrix:
         go-version:
           - stable
+          - 1.25.x
+          - 1.24.x
+          - 1.23.x
+          - 1.22.x
           - 1.21.x
           - 1.20.x
           - 1.19.x
@@ -20,11 +27,10 @@ jobs:
           - 1.14.x
           - 1.13.x
           - 1.12.x
-          - 1.11.x
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v6
     - name: Set up Go ${{ matrix.go-version }}
-      uses: actions/setup-go@v4
+      uses: actions/setup-go@v6
       with:
         go-version: ${{ matrix.go-version }}
 

install_test.go

@@ -4,12 +4,17 @@
 package main
 
 import (
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"testing"
+
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace ioutil.TempDir with os.MkdirTemp when minimum Go version
+	// is raised to 1.16+. See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
 )
 
 func TestBootstrap(t *testing.T) {
@@ -27,7 +32,19 @@ func TestBootstrap(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		name += ".exe"
 	}
-	if _, err := os.Stat(filepath.Join(os.Getenv("GOPATH"), "bin", name)); err != nil {
+
+	// Use `go env GOBIN` to determine install location, as GOPATH may not be
+	// set in module-aware mode. Falls back to GOPATH/bin if GOBIN is empty.
+	binDir, err := run("go", "env", "GOBIN")
+	if err != nil {
+		t.Fatalf("failed to get GOBIN: %v", err)
+	}
+	binDir = strings.TrimSpace(binDir)
+	if binDir == "" {
+		binDir = filepath.Join(os.Getenv("GOPATH"), "bin")
+	}
+
+	if _, err := os.Stat(filepath.Join(binDir, name)); err != nil {
 		t.Fatal(err)
 	}
 }

internal/run.go

@@ -3,12 +3,16 @@ package internal
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"runtime"
 	"strings"
+
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace ioutil.Discard with io.Discard when minimum Go version
+	// is raised to 1.16+. See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
 )
 
 var debug *log.Logger = log.New(ioutil.Discard, "", 0)

mage/main.go

@@ -8,7 +8,6 @@ import (
 	"fmt"
 	"go/build"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -22,6 +21,12 @@ import (
 	"text/template"
 	"time"
 
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace ioutil.Discard with io.Discard and ioutil.ReadDir with
+	// os.ReadDir when minimum Go version is raised to 1.16+.
+	// See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
+
 	"github.com/magefile/mage/internal"
 	"github.com/magefile/mage/mg"
 	"github.com/magefile/mage/parse"

mage/main_test.go

@@ -12,7 +12,6 @@ import (
 	"go/parser"
 	"go/token"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -26,6 +25,12 @@ import (
 	"testing"
 	"time"
 
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace with os.MkdirTemp, os.WriteFile, and io.Discard when
+	// minimum Go version is raised to 1.16+.
+	// See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
+
 	"github.com/magefile/mage/internal"
 	"github.com/magefile/mage/mg"
 )

mage/template.go

@@ -3,6 +3,11 @@ package mage
 // this template uses the "data"
 
 // var only for tests
+//
+// NOTE: This template generates code that uses io/ioutil which was deprecated
+// in Go 1.16. When mage's minimum Go version is raised to 1.16+, update
+// _ioutil "io/ioutil" to _io "io" and _ioutil.Discard to _io.Discard.
+// See: https://go.dev/doc/go1.16#ioutil
 var mageMainfileTplString = `//go:build ignore
 // +build ignore
 

mage/testdata/setdir/setdir.go

@@ -5,8 +5,12 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"strings"
+
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace ioutil.ReadDir with os.ReadDir when minimum Go version
+	// is raised to 1.16+. See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
 )
 
 func TestCurrentDir() error {

mage/testdata/setworkdir/magefile.go

@@ -5,8 +5,12 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"strings"
+
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace ioutil.ReadDir with os.ReadDir when minimum Go version
+	// is raised to 1.16+. See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
 )
 
 func TestWorkingDir() error {

parse/parse.go

@@ -7,13 +7,17 @@ import (
 	"go/doc"
 	"go/parser"
 	"go/token"
-	"io/ioutil"
 	"log"
 	"os"
 	"sort"
 	"strings"
 	"time"
 
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace ioutil.Discard with io.Discard when minimum Go version
+	// is raised to 1.16+. See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
+
 	"github.com/magefile/mage/internal"
 )
 

parse/testdata/subcommands.go

@@ -5,6 +5,11 @@ package main
 
 import "github.com/magefile/mage/mg"
 
+// Foo is a type alias to test that type aliases don't cause panics during
+// parsing. See issue #126. Type aliases were introduced in Go 1.9, which is
+// now well below the minimum supported version (1.12).
+type Foo = map[string]string
+
 type Build mg.Namespace
 
 func (Build) Foobar() error {

sh/helpers_test.go

@@ -3,11 +3,16 @@ package sh_test
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
 
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace with os.ReadFile, os.MkdirTemp, and os.WriteFile when
+	// minimum Go version is raised to 1.16+.
+	// See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
+
 	"github.com/magefile/mage/sh"
 )
 

target/newer_test.go

@@ -1,11 +1,15 @@
 package target
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
 	"time"
+
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace with os.MkdirTemp and os.WriteFile when minimum Go
+	// version is raised to 1.16+. See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
 )
 
 func TestNewestModTime(t *testing.T) {

target/target_test.go

@@ -1,11 +1,15 @@
 package target
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
 	"time"
+
+	// DEPRECATED: The ioutil package was deprecated in Go 1.16.
+	// TODO: Replace with os.MkdirTemp and os.WriteFile when minimum Go
+	// version is raised to 1.16+. See: https://go.dev/doc/go1.16#ioutil
+	"io/ioutil"
 )
 
 func TestPathMissingDest(t *testing.T) {