Replace homegrown map-to-structure code by using package mapstructure.

4 files changed, 28 insertions, 41 deletions

diff --git a/go.mod b/go.mod
index 20f6f94..cd0684c 100644
--- a/go.mod
+++ b/go.mod
@@ -14,6 +14,7 @@ require (
 	github.com/gabriel-vasile/mimetype v1.4.0
 	github.com/google/go-cmp v0.5.6
 	github.com/google/uuid v1.3.0
+	github.com/mitchellh/mapstructure v1.4.3
 	github.com/nightlyone/lockfile v1.0.0
 	golang.org/x/net v0.0.0-20210916014120-12bc252f5db8
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
diff --git a/go.sum b/go.sum
index 35c21da..56f286f 100644
--- a/go.sum
+++ b/go.sum
@@ -47,6 +47,8 @@ github.com/mattn/go-runewidth v0.0.4/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzp
 github.com/mattn/go-runewidth v0.0.8/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/mattn/go-runewidth v0.0.9 h1:Lm995f3rfxdpd6TSmuVCHVb/QhupuXlYr8sCI/QdE+0=
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/mitchellh/mapstructure v1.4.3 h1:OVowDSCllw/YjdLkam3/sm7wEtOy59d8ndGgCcyj8cs=
+github.com/mitchellh/mapstructure v1.4.3/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/mmcdole/goxpp v0.0.0-20181012175147-0068e33feabf h1:sWGE2v+hO0Nd4yFU/S/mDBM5plIU8v/Qhfz41hkDIAI=
 github.com/mmcdole/goxpp v0.0.0-20181012175147-0068e33feabf/go.mod h1:pasqhqstspkosTneA62Nc+2p9SOBBYAPbnmRRWPQ0V8=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 h1:ZqeYNhU3OHLH3mGKHDcjJRFFRrJa6eAM5H+CtDdOsPc=
diff --git a/pkg/config/yaml.go b/pkg/config/yaml.go
index a80c80d..3050825 100644
--- a/pkg/config/yaml.go
+++ b/pkg/config/yaml.go
@@ -4,9 +4,9 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"reflect"
 	"strings"
 
+	"github.com/mitchellh/mapstructure"
 	"gopkg.in/yaml.v3"
 
 	"github.com/Necoro/feed2imap-go/pkg/log"
@@ -139,50 +139,34 @@ func appTarget(target []string, app string) []string {
 	}
 }
 
-func buildOptions(globalFeedOptions *Options, options Map) (feedOptions Options, unknownFields []string) {
+func buildOptions(globalFeedOptions *Options, options Map) (Options, []string) {
+	// copy global as default
+	feedOptions := *globalFeedOptions
+
 	if options == nil {
 		// no options set for the feed: copy global options and be done
-		return *globalFeedOptions, unknownFields
+		return feedOptions, []string{}
 	}
 
-	fv := reflect.ValueOf(&feedOptions).Elem()
-	gv := reflect.ValueOf(globalFeedOptions).Elem()
-
-	n := gv.NumField()
-	for i := 0; i < n; i++ {
-		field := fv.Field(i)
-		f := fv.Type().Field(i)
-
-		if f.PkgPath != "" && !f.Anonymous {
-			continue
-		}
-
-		tag := f.Tag.Get("yaml")
-		if tag == "" {
-			continue
-		}
-
-		name := strings.Split(tag, ",")[0]
+	var md mapstructure.Metadata
+	mapstructureConfig := mapstructure.DecoderConfig{
+		TagName:  "yaml",
+		Metadata: &md,
+		Result:   &feedOptions,
+	}
 
-		set, ok := options[name]
-		if ok { // in the map -> copy and delete
-			value := reflect.ValueOf(set)
-			if !value.Type().AssignableTo(field.Type()) {
-				value = value.Convert(field.Type())
-			}
-			field.Set(value)
-			delete(options, name)
-		} else { // not in the map -> copy from global
-			field.Set(gv.Field(i))
-		}
+	var err error
+	dec, err := mapstructure.NewDecoder(&mapstructureConfig)
+	if err != nil {
+		panic(err)
 	}
 
-	// remaining fields are unknown
-	for k := range options {
-		unknownFields = append(unknownFields, k)
+	err = dec.Decode(options)
+	if err != nil {
+		panic(err)
 	}
 
-	return feedOptions, unknownFields
+	return feedOptions, md.Unused
 }
 
 // Fetch the group structure and populate the `targetStr` fields in the feeds
diff --git a/pkg/config/yaml_test.go b/pkg/config/yaml_test.go
index b02c4c4..b422c38 100644
--- a/pkg/config/yaml_test.go
+++ b/pkg/config/yaml_test.go
@@ -30,12 +30,12 @@ func TestBuildOptions(tst *testing.T) {
 		out      Options
 		unknowns []string
 	}{
-		{"Empty", nil, Options{}, Options{}, nil},
-		{"Simple copy", nil, Options{MinFreq: 75}, Options{MinFreq: 75}, nil},
+		{"Empty", nil, Options{}, Options{}, []string{}},
+		{"Simple copy", nil, Options{MinFreq: 75}, Options{MinFreq: 75}, []string{}},
 		{"Unknowns", Map{"foo": 1}, Options{}, Options{}, []string{"foo"}},
-		{"Override", Map{"include-images": true}, Options{InclImages: false}, Options{InclImages: true}, nil},
-		{"Non-Standard Type", Map{"body": "both"}, Options{}, Options{Body: "both"}, nil},
-		{"Mixed", Map{"min-frequency": 24}, Options{MinFreq: 6, InclImages: true}, Options{MinFreq: 24, InclImages: true}, nil},
+		{"Override", Map{"include-images": true}, Options{InclImages: false}, Options{InclImages: true}, []string{}},
+		{"Non-Standard Type", Map{"body": "both"}, Options{}, Options{Body: "both"}, []string{}},
+		{"Mixed", Map{"min-frequency": 24}, Options{MinFreq: 6, InclImages: true}, Options{MinFreq: 24, InclImages: true}, []string{}},
 		{"All",
 			Map{"max-frequency": 12, "include-images": true, "ignore-hash": true, "obsolete": 54},
 			Options{MinFreq: 6, InclImages: true, IgnHash: false},