Fixer and tests to remove deprecated 'vhd_temp_path' Hyper-V ISO setting

fix/fixer.go

@@ -36,6 +36,7 @@ func init() {
 		"amazon-private-ip":          new(FixerAmazonPrivateIP),
 		"docker-email":               new(FixerDockerEmail),
 		"powershell-escapes":         new(FixerPowerShellEscapes),
+		"hyperv-deprecations":        new(FixerHypervDeprecations),
 	}
 
 	FixerOrder = []string{
@@ -55,5 +56,6 @@ func init() {
 		"amazon-private-ip",
 		"docker-email",
 		"powershell-escapes",
+		"hyperv-deprecations",
 	}
 }

fix/fixer_hyperv_deprecations.go

@@ -0,0 +1,50 @@
+package fix
+
+import (
+	"github.com/mitchellh/mapstructure"
+)
+
+// FixerHypervDeprecations removes the deprecated "vhd_temp_path" setting
+// from Hyper-V ISO builder templates
+type FixerHypervDeprecations struct{}
+
+func (FixerHypervDeprecations) Fix(input map[string]interface{}) (map[string]interface{}, error) {
+	// The type we'll decode into; we only care about builders
+	type template struct {
+		Builders []map[string]interface{}
+	}
+
+	// Decode the input into our structure, if we can
+	var tpl template
+	if err := mapstructure.Decode(input, &tpl); err != nil {
+		return nil, err
+	}
+
+	for _, builder := range tpl.Builders {
+		builderTypeRaw, ok := builder["type"]
+		if !ok {
+			continue
+		}
+
+		builderType, ok := builderTypeRaw.(string)
+		if !ok {
+			continue
+		}
+
+		if builderType != "hyperv-iso" {
+			continue
+		}
+
+		_, ok = builder["vhd_temp_path"]
+		if ok {
+			delete(builder, "vhd_temp_path")
+		}
+	}
+
+	input["builders"] = tpl.Builders
+	return input, nil
+}
+
+func (FixerHypervDeprecations) Synopsis() string {
+	return `Removes the deprecated "vhd_temp_path" setting from Hyper-V ISO builder templates`
+}

fix/fixer_hyperv_deprecations_test.go

@@ -0,0 +1,60 @@
+package fix
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFixerHypervDeprecations_impl(t *testing.T) {
+	var _ Fixer = new(FixerHypervDeprecations)
+}
+
+func TestFixerHypervDeprecations_Fix(t *testing.T) {
+	cases := []struct {
+		Input    map[string]interface{}
+		Expected map[string]interface{}
+	}{
+		// No vhd_temp_path field in template - noop
+		{
+			Input: map[string]interface{}{
+				"type": "hyperv-iso",
+			},
+
+			Expected: map[string]interface{}{
+				"type": "hyperv-iso",
+			},
+		},
+
+		// Deprecated vhd_temp_path field in template should be deleted
+		{
+			Input: map[string]interface{}{
+				"type":          "hyperv-iso",
+				"vhd_temp_path": "foopath",
+			},
+
+			Expected: map[string]interface{}{
+				"type": "hyperv-iso",
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		var f FixerHypervDeprecations
+
+		input := map[string]interface{}{
+			"builders": []map[string]interface{}{tc.Input},
+		}
+
+		expected := map[string]interface{}{
+			"builders": []map[string]interface{}{tc.Expected},
+		}
+
+		output, err := f.Fix(input)
+		if err != nil {
+			t.Fatalf("err: %s", err)
+		}
+
+		assert.Equal(t, expected, output, "Should be equal")
+	}
+}