feat: allow for stdout to be buffered on each command (#2335)

* feat: add preRun func to version to restore stdout

Signed-off-by: Christopher Phillips <christopher.phillips@anchore.com>

* test: add test to capture version in output

Signed-off-by: Christopher Phillips <christopher.phillips@anchore.com>

* change stdout buffering to log to be opt-in per command

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

* fix tests

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

---------

Signed-off-by: Christopher Phillips <christopher.phillips@anchore.com>
Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>
Co-authored-by: Alex Goodman <wagoodman@users.noreply.github.com>

test/cli/version_cmd_test.go

@@ -0,0 +1,29 @@
+package cli
+
+import (
+	"testing"
+)
+
+func TestVersionCmdPrintsToStdout(t *testing.T) {
+	tests := []struct {
+		name       string
+		env        map[string]string
+		assertions []traitAssertion
+	}{
+		{
+			name: "version command prints to stdout",
+			assertions: []traitAssertion{
+				assertInOutput("Version:"),
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			pkgCmd, pkgsStdout, pkgsStderr := runSyft(t, test.env, "version")
+			for _, traitFn := range test.assertions {
+				traitFn(t, pkgsStdout, pkgsStderr, pkgCmd.ProcessState.ExitCode())
+			}
+		})
+	}
+}