refactor alias/default parsing to support imported packages and namespaces (#203)

fixes #192

Author: natefinch

internal/run.go

@@ -0,0 +1,114 @@
+package internal
+
+import (
+	"bytes"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+var debug *log.Logger = log.New(ioutil.Discard, "", 0)
+
+func SetDebug(l *log.Logger) {
+	debug = l
+}
+
+func RunDebug(cmd string, args ...string) error {
+	env, err := EnvWithCurrentGOOS()
+	if err != nil {
+		return err
+	}
+	buf := &bytes.Buffer{}
+	errbuf := &bytes.Buffer{}
+	debug.Println("running", cmd, strings.Join(args, " "))
+	c := exec.Command(cmd, args...)
+	c.Env = env
+	c.Stderr = errbuf
+	c.Stdout = buf
+	if err := c.Run(); err != nil {
+		debug.Print("error running '", cmd, strings.Join(args, " "), "': ", err, ": ", errbuf)
+		return err
+	}
+	debug.Println(buf)
+	return nil
+}
+
+func OutputDebug(cmd string, args ...string) (string, error) {
+	env, err := EnvWithCurrentGOOS()
+	if err != nil {
+		return "", err
+	}
+	buf := &bytes.Buffer{}
+	errbuf := &bytes.Buffer{}
+	debug.Println("running", cmd, strings.Join(args, " "))
+	c := exec.Command(cmd, args...)
+	c.Env = env
+	c.Stderr = errbuf
+	c.Stdout = buf
+	if err := c.Run(); err != nil {
+		debug.Print("error running '", cmd, strings.Join(args, " "), "': ", err, ": ", errbuf)
+		return "", err
+	}
+	return strings.TrimSpace(buf.String()), nil
+}
+
+// splitEnv takes the results from os.Environ() (a []string of foo=bar values)
+// and makes a map[string]string out of it.
+func splitEnv(env []string) (map[string]string, error) {
+	out := map[string]string{}
+
+	for _, s := range env {
+		parts := strings.SplitN(s, "=", 2)
+		if len(parts) != 2 {
+			return nil, fmt.Errorf("badly formatted environment variable: %v", s)
+		}
+		out[parts[0]] = parts[1]
+	}
+	return out, nil
+}
+
+// joinEnv converts the given map into a list of foo=bar environment variables,
+// such as that outputted by os.Environ().
+func joinEnv(env map[string]string) []string {
+	vals := make([]string, 0, len(env))
+	for k, v := range env {
+		vals = append(vals, k+"="+v)
+	}
+	return vals
+}
+
+// EnvWithCurrentGOOS returns a copy of os.Environ with the GOOS and GOARCH set
+// to runtime.GOOS and runtime.GOARCH.
+func EnvWithCurrentGOOS() ([]string, error) {
+	vals, err := splitEnv(os.Environ())
+	if err != nil {
+		return nil, err
+	}
+	vals["GOOS"] = runtime.GOOS
+	vals["GOARCH"] = runtime.GOARCH
+	return joinEnv(vals), nil
+}
+
+// EnvWithGOOS retuns the os.Environ() values with GOOS and/or GOARCH either set
+// to their runtime value, or the given value if non-empty.
+func EnvWithGOOS(goos, goarch string) ([]string, error) {
+	env, err := splitEnv(os.Environ())
+	if err != nil {
+		return nil, err
+	}
+	if goos == "" {
+		env["GOOS"] = runtime.GOOS
+	} else {
+		env["GOOS"] = goos
+	}
+	if goarch == "" {
+		env["GOARCH"] = runtime.GOARCH
+	} else {
+		env["GOARCH"] = goarch
+	}
+	return joinEnv(env), nil
+}

mage/import_test.go

@@ -23,10 +23,12 @@ func TestMageImportsList(t *testing.T) {
 	expected := `
 Targets:
   root               
-  zz:nS:deploy2      deploys stuff.
+  zz:nS:deploy2*     deploys stuff.
   zz:buildSubdir2    Builds stuff.
   nS:deploy          deploys stuff.
   buildSubdir        Builds stuff.
+
+* default target
 `[1:]
 
 	if actual != expected {
@@ -97,6 +99,9 @@ func TestMageImportsNamedRoot(t *testing.T) {
 	if actual != expected {
 		t.Fatalf("expected: %q got: %q", expected, actual)
 	}
+	if stderr := stderr.String(); stderr != "" {
+		t.Fatal("unexpected output to stderr: ", stderr)
+	}
 }
 
 func TestMageImportsRootImportNS(t *testing.T) {
@@ -140,3 +145,24 @@ func TestMageImportsRootImport(t *testing.T) {
 		t.Fatalf("expected: %q got: %q", expected, actual)
 	}
 }
+
+func TestMageImportsAliasToNS(t *testing.T) {
+	stdout := &bytes.Buffer{}
+	stderr := &bytes.Buffer{}
+	inv := Invocation{
+		Dir:    "./testdata/mageimport",
+		Stdout: stdout,
+		Stderr: stderr,
+		Args:   []string{"nsd2"},
+	}
+
+	code := Invoke(inv)
+	if code != 0 {
+		t.Fatalf("expected to exit with code 0, but got %v, stderr:\n%s", code, stderr)
+	}
+	actual := stdout.String()
+	expected := "deploy2\n"
+	if actual != expected {
+		t.Fatalf("expected: %q got: %q", expected, actual)
+	}
+}