[chore] refactor test/cliparsing.sh into a go test below internal/config (#1036)

Also adds AddGlobalFlags and AddServerFlags as methods on ConfigState,
very useful for testing.

internal/config/cliparsing_test.go

@@ -0,0 +1,206 @@
+/*
+   GoToSocial
+   Copyright (C) 2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package config_test
+
+import (
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
+	"github.com/stretchr/testify/assert"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"gopkg.in/yaml.v3"
+)
+
+func expectedKV(kvpairs ...string) map[string]interface{} {
+	ret := make(map[string]interface{}, len(kvpairs)/2)
+
+	for i := 0; i < len(kvpairs)-1; i += 2 {
+		ret[kvpairs[i]] = kvpairs[i+1]
+	}
+
+	return ret
+}
+
+func expectedFile(t *testing.T, file string) map[string]interface{} {
+	expectedConfig, err := os.ReadFile(file)
+	if err != nil {
+		t.Errorf("error reading expected config from file %q: %v", file, err)
+	}
+
+	var ret map[string]interface{}
+	if err := yaml.Unmarshal(expectedConfig, &ret); err != nil {
+		t.Errorf("error parsing expected config from file %q: %v", file, err)
+	}
+
+	return ret
+}
+
+func TestCLIParsing(t *testing.T) {
+	type testcase struct {
+		cli      []string
+		env      []string
+		expected map[string]interface{}
+	}
+
+	defaults, _ := config.Defaults.MarshalMap()
+
+	testcases := map[string]testcase{
+		"Make sure defaults are set correctly": {
+			expected: defaults,
+		},
+
+		"Override db-address from default using cli flag": {
+			cli: []string{
+				"--db-address", "some.db.address",
+			},
+			expected: expectedKV(
+				"db-address", "some.db.address",
+			),
+		},
+
+		"Override db-address from default using env var": {
+			env: []string{
+				"GTS_DB_ADDRESS=some.db.address",
+			},
+			expected: expectedKV(
+				"db-address", "some.db.address",
+			),
+		},
+
+		"Override db-address from default using both env var and cli flag. The cli flag should take priority": {
+			cli: []string{
+				"--db-address", "some.db.address",
+			},
+			env: []string{
+				"GTS_DB_ADDRESS=some.other.db.address",
+			},
+			expected: expectedKV(
+				"db-address", "some.db.address",
+			),
+		},
+
+		"Loading a config file via env var": {
+			env: []string{
+				"GTS_CONFIG_PATH=testdata/test.yaml",
+			},
+			expected: expectedFile(t, "testdata/test.yaml"),
+		},
+
+		"Loading a config file via cli flag": {
+			cli: []string{
+				"--config-path", "testdata/test.yaml",
+			},
+			expected: expectedFile(t, "testdata/test.yaml"),
+		},
+
+		"Loading a config file and overriding one of the variables with a cli flag": {
+			cli: []string{
+				"--config-path", "testdata/test.yaml",
+				"--account-domain", "my.test.domain",
+			},
+			// only checking our overridden one and one non-default from the config file here instead of including all of test.yaml
+			expected: expectedKV(
+				"account-domain", "my.test.domain",
+				"host", "gts.example.org",
+			),
+		},
+
+		"Loading a config file and overriding one of the variables with an env var": {
+			cli: []string{
+				"--config-path", "testdata/test.yaml",
+			},
+			env: []string{
+				"GTS_ACCOUNT_DOMAIN=my.test.domain",
+			},
+			// only checking our overridden one and one non-default from the config file here instead of including all of test.yaml
+			expected: expectedKV(
+				"account-domain", "my.test.domain",
+				"host", "gts.example.org",
+			),
+		},
+
+		"Loading a config file and overriding one of the variables with both an env var and a cli flag. The cli flag should have priority": {
+			cli: []string{
+				"--config-path", "testdata/test.yaml",
+				"--account-domain", "my.test.domain",
+			},
+			env: []string{
+				"GTS_ACCOUNT_DOMAIN=my.wrong.test.domain",
+			},
+			// only checking our overridden one and one non-default from the config file here instead of including all of test.yaml
+			expected: expectedKV(
+				"account-domain", "my.test.domain",
+				"host", "gts.example.org",
+			),
+		},
+
+		"Loading a config file from json": {
+			cli: []string{
+				"--config-path", "testdata/test.json",
+			},
+			expected: expectedFile(t, "testdata/test.json"),
+		},
+
+		"Loading a partial config file. Default values should be used apart from those set in the config file": {
+			cli: []string{
+				"--config-path", "testdata/test2.yaml",
+			},
+			expected: expectedKV(
+				"log-level", "trace",
+				"account-domain", "peepee.poopoo",
+				"application-name", "gotosocial",
+			),
+		},
+	}
+
+	for desc, data := range testcases {
+		t.Run(desc, func(t *testing.T) {
+			os.Clearenv()
+
+			if data.env != nil {
+				for _, s := range data.env {
+					kv := strings.SplitN(s, "=", 2)
+					os.Setenv(kv[0], kv[1])
+				}
+			}
+
+			state := config.NewState()
+			cmd := cobra.Command{}
+			state.AddGlobalFlags(&cmd)
+			state.AddServerFlags(&cmd)
+
+			if data.cli != nil {
+				cmd.ParseFlags(data.cli)
+			}
+
+			state.BindFlags(&cmd)
+
+			state.Reload()
+
+			state.Viper(func(v *viper.Viper) {
+				for k, ev := range data.expected {
+					assert.EqualValues(t, ev, v.Get(k))
+				}
+			})
+		})
+	}
+}