Add environment variable for setting format icons

README.md

@@ -41,6 +41,7 @@ is used to print the test names, and possibly test output, as the tests run. Mos
 outputs use color to highlight pass, fail, or skip.
 
 The `--format-icons` flag changes the icons used by `pkgname` and `testdox` formats.
+You can set the `GOTESTSUM_FORMAT_ICONS` environment variable, instead of the flag.
 The nerdfonts icons requires a font from [Nerd Fonts](https://www.nerdfonts.com/).
 
 Commonly used formats (see `--help` for a full list):

cmd/handler_test.go

@@ -33,6 +33,7 @@ func TestPostRunHook(t *testing.T) {
 	}
 
 	env.Patch(t, "GOTESTSUM_FORMAT", "short")
+	env.Patch(t, "GOTESTSUM_FORMAT_ICONS", "default")
 
 	exec := newExecFromTestData(t)
 	err = postRunHook(opts, exec)

cmd/main.go

@@ -65,7 +65,8 @@ func setupFlags(name string) (*pflag.FlagSet, *options) {
 	flags.BoolVar(&opts.formatOptions.UseHiVisibilityIcons, "format-hivis",
 		false, "use high visibility characters in some formats")
 	_ = flags.MarkHidden("format-hivis")
-	flags.StringVar(&opts.formatOptions.Icons, "format-icons", "",
+	flags.StringVar(&opts.formatOptions.Icons, "format-icons",
+		lookEnvWithDefault("GOTESTSUM_FORMAT_ICONS", ""),
 		"use different icons, see help for options")
 	flags.BoolVar(&opts.rawCommand, "raw-command", false,
 		"don't prepend 'go test -json' to the 'go test' command")

cmd/testdata/post-run-hook-expected

@@ -1,5 +1,6 @@
 GOTESTSUM_ELAPSED=0.000s
 GOTESTSUM_FORMAT=short
+GOTESTSUM_FORMAT_ICONS=default
 GOTESTSUM_JSONFILE=events.json
 GOTESTSUM_JSONFILE_TIMING_EVENTS=timing.json
 GOTESTSUM_JUNITFILE=junit.xml