bug/issue #2448 - manage special bash options when no shell is defined (#2449)

* bash without "-o pipefail" option when "bash" is not explicitely
defined in the workflow
* bonus: fix inverted expected and actual in TestGetGitHubContext assertions

pkg/model/workflow.go

@@ -572,6 +572,8 @@ type Step struct {
 	Uses               string            `yaml:"uses"`
 	Run                string            `yaml:"run"`
 	WorkingDirectory   string            `yaml:"working-directory"`
+	// WorkflowShell is the shell really configured in the job, directly at step level or higher in defaults.run.shell
+	WorkflowShell      string            `yaml:"-"`
 	Shell              string            `yaml:"shell"`
 	Env                yaml.Node         `yaml:"env"`
 	With               map[string]string `yaml:"with"`
@@ -614,8 +616,14 @@ func (s *Step) ShellCommand() string {
 
 	//Reference: https://github.com/actions/runner/blob/8109c962f09d9acc473d92c595ff43afceddb347/src/Runner.Worker/Handlers/ScriptHandlerHelpers.cs#L9-L17
 	switch s.Shell {
-	case "", "bash":
-		shellCommand = "bash --noprofile --norc -e -o pipefail {0}"
+	case "":
+		shellCommand = "bash -e {0}"
+	case "bash":
+		if s.WorkflowShell == "" {
+			shellCommand = "bash -e {0}"
+		} else {
+			shellCommand = "bash --noprofile --norc -e -o pipefail {0}"
+		}
 	case "pwsh":
 		shellCommand = "pwsh -command . '{0}'"
 	case "python":

pkg/model/workflow_test.go

@@ -397,15 +397,18 @@ func TestReadWorkflow_Strategy(t *testing.T) {
 func TestStep_ShellCommand(t *testing.T) {
 	tests := []struct {
 		shell string
+		workflowShell string
 		want  string
 	}{
-		{"pwsh -v '. {0}'", "pwsh -v '. {0}'"},
-		{"pwsh", "pwsh -command . '{0}'"},
-		{"powershell", "powershell -command . '{0}'"},
+		{"pwsh -v '. {0}'", "", "pwsh -v '. {0}'"},
+		{"pwsh", "", "pwsh -command . '{0}'"},
+		{"powershell", "", "powershell -command . '{0}'"},
+		{"bash", "", "bash -e {0}"},
+		{"bash", "bash", "bash --noprofile --norc -e -o pipefail {0}"},
 	}
 	for _, tt := range tests {
 		t.Run(tt.shell, func(t *testing.T) {
-			got := (&Step{Shell: tt.shell}).ShellCommand()
+			got := (&Step{Shell: tt.shell, WorkflowShell: tt.workflowShell}).ShellCommand()
 			assert.Equal(t, got, tt.want)
 		})
 	}