feat: introduce abra config file and load abra dir from it (!419)

This is the first step to introduce a configuration file for abra. The config file must be named `abra.yaml` or àbra.yml`. abra look for the config file in the current directory and when not found traverses the directory tree up until it is found or the home/root directory is reached.

For now there is only one setting that is made configurable: `abraDir`. The new logic for setting the abra dir is the following:
1. lookup `$ABRA_DIR` env
2. look for config file and take value from there
3. `$HOME/.abra` as fallback

See coop-cloud/organising#303.

Reviewed-on: coop-cloud/abra#419
Reviewed-by: decentral1se <decentral1se@noreply.git.coopcloud.tech>
Co-authored-by: p4u1 <p4u1_f4u1@riseup.net>
Co-committed-by: p4u1 <p4u1_f4u1@riseup.net>

pkg/config/abra_test.go

@@ -0,0 +1,103 @@
+package config
+
+import (
+	"log"
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestFindAbraConfig(t *testing.T) {
+	wd, err := os.Getwd()
+	if err != nil {
+		log.Fatal(err)
+	}
+	tests := []struct {
+		Dir    string
+		Config string
+	}{
+		{
+			Dir:    "testdata/abraconfig1",
+			Config: filepath.Join(wd, "testdata/abraconfig1/abra.yaml"),
+		},
+		{
+			Dir:    "testdata/abraconfig1/subdir",
+			Config: filepath.Join(wd, "testdata/abraconfig1/abra.yaml"),
+		},
+		{
+			Dir:    "testdata/abraconfig2",
+			Config: filepath.Join(wd, "testdata/abraconfig2/abra.yml"),
+		},
+		{
+			Dir:    "testdata/abraconfig2/subdir",
+			Config: filepath.Join(wd, "testdata/abraconfig2/abra.yml"),
+		},
+		{
+			Dir:    "testdata",
+			Config: "",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.Dir, func(t *testing.T) {
+			config := findAbraConfig(tc.Dir)
+			if config != tc.Config {
+				t.Errorf("\nwant: %s\ngot:  %s", tc.Config, config)
+			}
+		})
+	}
+}
+
+func TestLoadAbraConfigGetAbraDir(t *testing.T) {
+	wd, err := os.Getwd()
+	if err != nil {
+		log.Fatal(err)
+	}
+	t.Setenv("ABRA_DIR", "")
+
+	t.Run("default", func(t *testing.T) {
+		cfg := LoadAbraConfig()
+		wantAbraDir := os.ExpandEnv("$HOME/.abra")
+		if cfg.GetAbraDir() != wantAbraDir {
+			t.Errorf("\nwant: %s\ngot:  %s", wantAbraDir, cfg.GetAbraDir())
+		}
+	})
+
+	t.Run("from config file", func(t *testing.T) {
+		t.Cleanup(func() { os.Chdir(wd) })
+		err = os.Chdir(filepath.Join(wd, "testdata/abraconfig1"))
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		cfg := LoadAbraConfig()
+		log.Println(cfg.GetAbraDir())
+		wantAbraDir := filepath.Join(wd, "testdata/abraconfig1/abra.yaml/foobar")
+		if cfg.GetAbraDir() != wantAbraDir {
+			t.Errorf("\nwant: %s\ngot:  %s", wantAbraDir, cfg.GetAbraDir())
+		}
+	})
+
+	t.Run("default when config file is empty", func(t *testing.T) {
+		t.Cleanup(func() { os.Chdir(wd) })
+		err := os.Chdir(filepath.Join(wd, "testdata/abraconfig2"))
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		cfg := LoadAbraConfig()
+		wantAbraDir := os.ExpandEnv("$HOME/.abra")
+		if cfg.GetAbraDir() != wantAbraDir {
+			t.Errorf("\nwant: %s\ngot:  %s", wantAbraDir, cfg.GetAbraDir())
+		}
+	})
+
+	t.Run("from env variable", func(t *testing.T) {
+		t.Setenv("ABRA_DIR", "foo")
+		cfg := LoadAbraConfig()
+		wantAbraDir := "foo"
+		if cfg.GetAbraDir() != wantAbraDir {
+			t.Errorf("\nwant: %s\ngot:  %s", wantAbraDir, cfg.GetAbraDir())
+		}
+	})
+}