test: Add a test for --ssh option in finch build command (#101)

The following pull request attempts to modify the finch build command to
allow the --ssh option.

- runfinch/finch#696

Therefore, this commit adds a test to run finch build with the --ssh
option.

Issue #, if available: N/A

*Description of changes:* Details are described in this commit message.

*Testing done:* Yes



- [x] I've reviewed the guidance in CONTRIBUTING.md


#### License Acceptance

By submitting this pull request, I confirm that my contribution is made
under the terms of the Apache 2.0 license.

Signed-off-by: Hayato Kiwata <[email protected]>

tests/build.go

@@ -19,7 +19,7 @@ import (
 
 // Build command building an image.
 //
-// TODO:  --no-cache, --ssh, syntax check for docker files
+// TODO:  --no-cache, syntax check for docker files
 // --no-cache flag is added to tests asserting the output from `RUN` command.
 // [Discussion]: https://github.com/runfinch/common-tests/pull/4#discussion_r971338825
 func Build(o *option.Option) {
@@ -126,6 +126,16 @@ func Build(o *option.Option) {
 				gomega.Expect(ffs.CheckIfFileExists(outputFilePath)).To(gomega.Equal(true))
 			})
 
+			ginkgo.It("Build an image with --ssh option", func() {
+				containerWithSSH := fmt.Sprintf(`FROM %s
+				RUN ["echo", "built from Dockerfile.with-ssh"]
+			`, defaultImage)
+				dockerFilePath := filepath.Join(buildContext, "Dockerfile.with-ssh")
+				ffs.WriteFile(dockerFilePath, containerWithSSH)
+				stdErr := command.Stderr(o, "build", "--ssh", "default", "-f", dockerFilePath, buildContext)
+				gomega.Expect(stdErr).Should(gomega.ContainSubstring("built from Dockerfile.with-ssh"))
+			})
+
 			ginkgo.Context("Docker file syntax tests", func() {
 				negativeTests := []struct {
 					test         string