ref(_tests): add a custom matcher just for command output

Author: arschles

_tests/apps_test.go

@@ -14,37 +14,34 @@ var _ = Describe("Apps", func() {
 		})
 
 		It("can't get app info", func() {
-			output, err := execute("deis info -a %s", app1Name)
-			Expect(err).To(HaveOccurred())
-			Expect(output).To(ContainSubstring("NOT FOUND"))
+			Expect(execute("deis info -a %s", app1Name)).To(SucceedWithOutput(ContainSubstring("NOT FOUND")))
 		})
 
 		It("can't get app logs", func() {
-			output, err := execute("deis logs -a %s", app1Name)
-			Expect(err).To(HaveOccurred())
-			Expect(output).To(ContainSubstring("NOT FOUND"))
+			out := execute("deis logs -a %s", app1Name)
+			Expect(out.err).To(HaveOccurred())
+			Expect(out.str).To(ContainSubstring("NOT FOUND"))
 		})
 
 		// TODO: this currently returns "Error: json: cannot unmarshal object into Go value of type []interface {}"
 		XIt("can't run a command in the app environment", func() {
-			output, err := execute("deis apps:run echo Hello, 世界")
-			Expect(err).To(HaveOccurred())
-			Expect(output).To(ContainSubstring("NOT FOUND"))
+			out := execute("deis apps:run echo Hello, 世界")
+			Expect(out.err).To(HaveOccurred())
+			Expect(out.str).To(ContainSubstring("NOT FOUND"))
 		})
 
 		It("can create an app", func() {
-			output, err := execute("deis apps:create %s", app1Name)
-			Expect(err).NotTo(HaveOccurred())
-			Expect(output).To(SatisfyAll(
+			Expect(execute("deis apps:create %s", app1Name)).To(SucceedWithOutput(
 				ContainSubstring("Creating Application... done, created %s", app1Name),
 				ContainSubstring("Git remote deis added"),
-				ContainSubstring("remote available at ")))
-			output, err = execute("deis apps:destroy --confirm=%s", app1Name)
-			Expect(err).NotTo(HaveOccurred())
-			Expect(output).To(SatisfyAll(
+				ContainSubstring("remote available at "),
+			))
+
+			Expect(execute("deis apps:destroy --confirm=%s", app1Name)).To(SucceedWithOutput(
 				ContainSubstring("Destroying %s...", app1Name),
 				ContainSubstring("done in "),
-				ContainSubstring("Git remote deis removed")))
+				ContainSubstring("Git remote deis removed"),
+			))
 		})
 
 		It("can create an app with no git remote", func() {

_tests/auth_test.go

@@ -12,10 +12,10 @@ var _ = Describe("Auth", func() {
 		})
 
 		It("won't print the current user", func() {
-			output, err := execute("deis auth:whoami")
-			Expect(err).To(HaveOccurred())
-			Expect(output).To(ContainSubstring("Not logged in."))
-			Expect(output).NotTo(ContainSubstring(testUser))
+			Expect(execute("deis auth:whoami")).To(BeASuccessfulCommandWithOutputMatching(
+				ContainSubstring("Not logged in."),
+				ContainSubstring(testUser),
+			))
 		})
 	})
 
@@ -30,21 +30,21 @@ var _ = Describe("Auth", func() {
 
 		It("won't register twice", func() {
 			cmd := "deis register %s --username=%s --password=%s --email=%s"
-			output, err := execute(cmd, url, testUser, testPassword, testEmail)
-			Expect(err).To(HaveOccurred())
-			Expect(output).To(ContainSubstring("Registration failed"))
+			out := execute(cmd, url, testUser, testPassword, testEmail)
+			Expect(out.err).To(HaveOccurred())
+			Expect(out.str).To(ContainSubstring("Registration failed"))
 		})
 
 		It("prints the current user", func() {
-			output, err := execute("deis auth:whoami")
-			Expect(err).NotTo(HaveOccurred())
-			Expect(output).To(ContainSubstring("You are %s", testUser))
+			Expect(execute("deis auth:whoami")).To(SucceedWithOutput(
+				ContainSubstring("You are %s", testUser),
+			))
 		})
 
 		It("regenerates the token for the current user", func() {
-			output, err := execute("deis auth:regenerate")
-			Expect(err).NotTo(HaveOccurred())
-			Expect(output).To(ContainSubstring("Token Regenerated"))
+			Expect(execute("deis auth:regenerate")).To(SucceedWithOutput(
+				ContainSubstring("Token Regenerated"),
+			))
 		})
 	})
 

_tests/cmd_test.go

@@ -0,0 +1,90 @@
+package _tests_test
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"github.com/onsi/gomega/types"
+	"os/exec"
+	"strings"
+)
+
+// cmdOut is the output of a command. it's used by cmdMatcher to match on
+type cmdOut struct {
+	args []string
+	str  string
+	err  error
+}
+
+// execute executes the command generated by fmt.Sprintf(cmdLine, args...) and returns its output as a cmdOut structure.
+// this structure can then be matched upon using the SucceedWithOutput matcher below
+func execute(cmdLine string, args ...interface{}) *cmdOut {
+	var stdout, stderr bytes.Buffer
+	var cmd *exec.Cmd
+	cmd = exec.Command("/bin/sh", "-c", fmt.Sprintf(cmdLine, args...))
+	cmd.Stdout, cmd.Stderr = &stdout, &stderr
+	ret := &cmdOut{}
+	ret.args = cmd.Args
+	ret.str = stdout.String()
+	if err := cmd.Run(); err != nil {
+		ret.err = err
+		return ret
+	}
+	return ret
+}
+
+var (
+	errExpectedCmdOut = errors.New("cmdMatcher expects a *cmdOut")
+	errFailedCmd      = errors.New("command failed")
+)
+
+// Command
+type successfulCmdMatcher struct {
+	// will be filled in when Match is called
+	cmdo     *cmdOut
+	matchers []types.GomegaMatcher
+}
+
+// SucceedWithOutput returns a matcher that will match on a *cmdOut, ensuring that the command returned no error
+// and its output matches all the given matchers
+func SucceedWithOutput(matchers ...types.GomegaMatcher) types.GomegaMatcher {
+	return &successfulCmdMatcher{matchers: matchers}
+}
+
+// Match is the interface implementation of github.com/onsi/gomega/types.GomegaMatcher
+func (c *successfulCmdMatcher) Match(actual interface{}) (bool, error) {
+	cmdo, ok := actual.(*cmdOut)
+	if !ok {
+		return false, errExpectedCmdOut
+	}
+	c.cmdo = cmdo
+	if cmdo.err != nil {
+		return false, errFailedCmd
+	}
+	return SatisfyAll(c.matchers...)
+}
+
+// FailureMessage is the interface implementation of github.com/onsi/gomega/types.GomegaMatcher
+func (c *successfulCmdMatcher) FailureMessage(actual interface{}) string {
+	if c.cmdo == nil {
+		return "command failed, but wasn't recorded"
+	}
+	return fmt.Sprintf("command %s errored.\noutput:\n%s\nerror:%s\n",
+		strings.Join(c.cmdo.args, " "),
+		c.cmdo.str,
+		c.cmdo.err,
+	)
+}
+
+// NegatedFailureMessage is the interface implementation of github.com/onsi/gomega/types.GomegaMatcher
+func (c *successfulCmdMatcher) NegatedFailureMessage(actual interface{}) string {
+	if c.cmdo == nil {
+		return "command failed, but wasn't recorded"
+	}
+
+	return fmt.Sprintf("command %s errored.\noutput:\n%s\nerror:%s\n",
+		strings.Join(c.cmdo.args, " "),
+		c.cmdo.str,
+		c.cmdo.err,
+	)
+}

_tests/config_test.go

@@ -14,7 +14,7 @@ var _ = Describe("Config", func() {
 
 		It("can create a new app", func() {
 			output, err := execute("deis apps:create %s", appName)
-			Expect(err).NotTo(HaveOccurred())
+			Expect(err).To(BeNil())
 			Expect(output).To(SatisfyAll(
 				ContainSubstring("Creating Application... done, created %s", appName),
 				ContainSubstring("Git remote deis added"),

_tests/tests_suite_test.go

@@ -1,7 +1,6 @@
 package _tests_test
 
 import (
-	"bytes"
 	"fmt"
 	"math/rand"
 	"os"
@@ -105,17 +104,6 @@ func logout() {
 	Expect(output).To(Equal("Logged out\n"))
 }
 
-func execute(cmdLine string, args ...interface{}) (string, error) {
-	var stdout, stderr bytes.Buffer
-	var cmd *exec.Cmd
-	cmd = exec.Command("/bin/sh", "-c", fmt.Sprintf(cmdLine, args...))
-	cmd.Stdout, cmd.Stderr = &stdout, &stderr
-	if err := cmd.Run(); err != nil {
-		return stderr.String(), err
-	}
-	return stdout.String(), nil
-}
-
 func createKey(name string) {
 	var home string
 	if user, err := user.Current(); err != nil {