Merge pull request #4 from rogpeppe/004-testscript-cleanup

testscript: minor cleanups

.travis.yml

@@ -0,0 +1,5 @@
+language: go
+go_import_path: github.com/rogpeppe/modinternal
+go: 
+  - "1.11"
+script: go test ./...

testscript/doc.go

@@ -23,13 +23,15 @@ To run a specific script foo.txt
 
 where TestName is the name of the test that Run is called from.
 
-To define an executable command that can be run as part of the script,
-the command should be registered inside a TestMain function before calling
-M.Run. For example:
+To define an executable command (or several) that can be run as part of the script,
+call RunMain with the functions that implement the command's functionality.
+The command functions will be called in a separate process, so are
+free to mutate global variables without polluting the top level test binary.
 
 	func TestMain(m *testing.M) {
-		testscript.RegisterCommand("testscript", testscriptMain)
-		os.Exit(m.Run())
+		os.Exit(testscript.RunMain(m, map[string] func() int{
+			"testscript": testscriptMain,
+		}))
 	}
 
 In general script files should have short names: a few words, not whole sentences.

testscript/testscript.go

@@ -40,6 +40,7 @@ type Env struct {
 	Cd      string
 }
 
+// Params holds parameters for a call to Run.
 type Params struct {
 	// Dir holds the name of the directory holding the scripts.
 	// All files in the directory with a .txt suffix will be considered
@@ -538,39 +539,6 @@ func diff(text1, text2 string) string {
 	return buf.String()
 }
 
-var diffTests = []struct {
-	text1 string
-	text2 string
-	diff  string
-}{
-	{"a b c", "a b d e f", "a b -c +d +e +f"},
-	{"", "a b c", "+a +b +c"},
-	{"a b c", "", "-a -b -c"},
-	{"a b c", "d e f", "-a -b -c +d +e +f"},
-	{"a b c d e f", "a b d e f", "a b -c d e f"},
-	{"a b c e f", "a b c d e f", "a b c +d e f"},
-}
-
-func TestDiff(t *testing.T) {
-	for _, tt := range diffTests {
-		// Turn spaces into \n.
-		text1 := strings.Replace(tt.text1, " ", "\n", -1)
-		if text1 != "" {
-			text1 += "\n"
-		}
-		text2 := strings.Replace(tt.text2, " ", "\n", -1)
-		if text2 != "" {
-			text2 += "\n"
-		}
-		out := diff(text1, text2)
-		// Cut final \n, cut spaces, turn remaining \n into spaces.
-		out = strings.Replace(strings.Replace(strings.TrimSuffix(out, "\n"), " ", "", -1), "\n", " ", -1)
-		if out != tt.diff {
-			t.Errorf("diff(%q, %q) = %q, want %q", text1, text2, out, tt.diff)
-		}
-	}
-}
-
 func removeAll(dir string) error {
 	// module cache has 0444 directories;
 	// make them writable in order to remove content.

testscript/testscript_test.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 	"testing"
 )
 
@@ -35,3 +36,36 @@ func TestSimple(t *testing.T) {
 	})
 	// TODO check that the temp directory has been removed.
 }
+
+var diffTests = []struct {
+	text1 string
+	text2 string
+	diff  string
+}{
+	{"a b c", "a b d e f", "a b -c +d +e +f"},
+	{"", "a b c", "+a +b +c"},
+	{"a b c", "", "-a -b -c"},
+	{"a b c", "d e f", "-a -b -c +d +e +f"},
+	{"a b c d e f", "a b d e f", "a b -c d e f"},
+	{"a b c e f", "a b c d e f", "a b c +d e f"},
+}
+
+func TestDiff(t *testing.T) {
+	for _, tt := range diffTests {
+		// Turn spaces into \n.
+		text1 := strings.Replace(tt.text1, " ", "\n", -1)
+		if text1 != "" {
+			text1 += "\n"
+		}
+		text2 := strings.Replace(tt.text2, " ", "\n", -1)
+		if text2 != "" {
+			text2 += "\n"
+		}
+		out := diff(text1, text2)
+		// Cut final \n, cut spaces, turn remaining \n into spaces.
+		out = strings.Replace(strings.Replace(strings.TrimSuffix(out, "\n"), " ", "", -1), "\n", " ", -1)
+		if out != tt.diff {
+			t.Errorf("diff(%q, %q) = %q, want %q", text1, text2, out, tt.diff)
+		}
+	}
+}