ability to set environment variable in shell script

CHANGELOG.md

@@ -4,6 +4,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Unreleased
 ### Added
 - semver environment variables
+- optional environment variables in scripts
 
 ## [1.1.0] - 2019-07-14
 ### Added

shell/powershell/powershell.go

@@ -26,8 +26,15 @@ func Command() (string, []string) {
 
 // Script converts a slice of individual shell commands to
 // a powershell script.
-func Script(commands []string) string {
-	var buf bytes.Buffer
+func Script(commands []string, environ map[string]string) string {
+	buf := new(bytes.Buffer)
+	for k, v := range environ {
+		fmt.Fprintln(buf)
+		fmt.Fprintf(buf, exportScript, k, v)
+	}
+	fmt.Fprintln(buf)
+	fmt.Fprintf(buf, optionScript)
+	fmt.Fprintln(buf)
 	for _, command := range commands {
 		escaped := fmt.Sprintf("%q", "+ "+command)
 		escaped = strings.Replace(escaped, "$", "`$", -1)
@@ -37,18 +44,16 @@ func Script(commands []string) string {
 			command,
 		))
 	}
-	return fmt.Sprintf(
-		buildScript,
-		buf.String(),
-	)
+	return buf.String()
 }
 
-// buildScript is a helper script this is added to the build
-// to prepare the environment and execute the build commands.
-const buildScript = `
-$erroractionpreference = "stop"
-%s
-`
+// optionScript is a helper script this is added to the build
+// to set shell options, in this case, to exit on error.
+const optionScript = `$erroractionpreference = "stop"`
+
+// exportScript is a helper script that is added to
+// the build script to export environment variables.
+const exportScript = "$Env:%s = %q"
 
 // traceScript is a helper script that is added to
 // the build script to trace a command.

shell/powershell/powershell_test.go

@@ -30,7 +30,15 @@ func TestCommands(t *testing.T) {
 }
 
 func TestScript(t *testing.T) {
-	got, want := Script([]string{"go build", "go test"}), exampleScript
+	got, want := Script([]string{"go build", "go test"}, nil), exampleScript
+	if got != want {
+		t.Errorf("Want %q, got %q", want, got)
+	}
+}
+
+func TestScriptEnviron(t *testing.T) {
+	env := map[string]string{"GOOS": "linux"}
+	got, want := Script([]string{"go build", "go test"}, env), exampleScriptEnviron
 	if got != want {
 		t.Errorf("Want %q, got %q", want, got)
 	}
@@ -44,5 +52,15 @@ go build
 
 echo "+ go test"
 go test
+`
 
+var exampleScriptEnviron = `
+$Env:GOOS = "linux"
+$erroractionpreference = "stop"
+
+echo "+ go build"
+go build
+
+echo "+ go test"
+go test
 `

shell/shell.go

@@ -25,8 +25,15 @@ func Command() (string, []string) {
 
 // Script converts a slice of individual shell commands to
 // a posix-compliant shell script.
-func Script(commands []string) string {
-	var buf bytes.Buffer
+func Script(commands []string, environ map[string]string) string {
+	buf := new(bytes.Buffer)
+	for k, v := range environ {
+		fmt.Fprintln(buf)
+		fmt.Fprintf(buf, exportScript, k, v)
+	}
+	fmt.Fprintln(buf)
+	fmt.Fprintf(buf, optionScript)
+	fmt.Fprintln(buf)
 	for _, command := range commands {
 		escaped := fmt.Sprintf("%q", command)
 		escaped = strings.Replace(escaped, "$", `\$`, -1)
@@ -36,18 +43,16 @@ func Script(commands []string) string {
 			command,
 		))
 	}
-	return fmt.Sprintf(
-		buildScript,
-		buf.String(),
-	)
+	return buf.String()
 }
 
-// buildScript is a helper script this is added to the build
-// to prepare the environment and execute the build commands.
-const buildScript = `
-set -e
-%s
-`
+// optionScript is a helper script this is added to the build
+// to set shell options, in this case, to exit on error.
+const optionScript = "set -e"
+
+// exportScript is a helper script that is added to
+// the build script to export environment variables.
+const exportScript = "export %s=%q"
 
 // traceScript is a helper script that is added to
 // the build script to trace a command.

shell/shell_test.go

@@ -28,7 +28,15 @@ func TestCommands(t *testing.T) {
 }
 
 func TestScript(t *testing.T) {
-	got, want := Script([]string{"go build", "go test"}), exampleScript
+	got, want := Script([]string{"go build", "go test"}, nil), exampleScript
+	if got != want {
+		t.Errorf("Want %q, got %q", want, got)
+	}
+}
+
+func TestScriptEnviron(t *testing.T) {
+	env := map[string]string{"GOOS": "linux"}
+	got, want := Script([]string{"go build", "go test"}, env), exampleScriptEnviron
 	if got != want {
 		t.Errorf("Want %q, got %q", want, got)
 	}
@@ -42,5 +50,15 @@ go build
 
 echo + "go test"
 go test
+`
 
+var exampleScriptEnviron = `
+export GOOS="linux"
+set -e
+
+echo + "go build"
+go build
+
+echo + "go test"
+go test
 `

shell/shell_windows.go

@@ -18,6 +18,6 @@ func Command() (string, []string) {
 
 // Script converts a slice of individual shell commands to
 // a powershell script.
-func Script(commands []string) string {
-	return powershell.Script(commands)
+func Script(commands []string, environ map[string]string) string {
+	return powershell.Script(commands, environ)
 }