Merge pull request #10 from vaskoz/schemamapping

schema mapping problem

schema_mapping/schema.go

@@ -0,0 +1,30 @@
+package schema
+
+// Field represents a field that has aliases used by other fields.
+type Field struct {
+	name    string
+	aliases []string
+}
+
+// Schema is a list of Fields.
+type Schema struct {
+	fields []Field
+}
+
+// Mapping takes two schemas and returns a map of field names between schemas.
+func Mapping(src, target Schema) map[string]string {
+	aliasMap := make(map[string]string)
+	for _, field := range target.fields {
+		aliasMap[field.name] = field.name
+		for _, alias := range field.aliases {
+			aliasMap[alias] = field.name
+		}
+	}
+	result := make(map[string]string)
+	for _, field := range src.fields {
+		if _, found := aliasMap[field.name]; found {
+			result[field.name] = aliasMap[field.name]
+		}
+	}
+	return result
+}

schema_mapping/schema_test.go

@@ -0,0 +1,47 @@
+package schema
+
+import (
+	"reflect"
+	"testing"
+)
+
+var testcases = []struct {
+	src, target Schema
+	expected    map[string]string
+}{
+	{src: Schema{[]Field{{"country", []string{"cnt", "countryLong"}}}},
+		target:   Schema{[]Field{{"countryLong", []string{"country"}}}},
+		expected: map[string]string{"country": "countryLong"}},
+	{src: Schema{[]Field{
+		{"country", []string{"nationality"}},
+		{"state", []string{"st", "territory"}},
+		{"city", []string{"cty", "burrow"}},
+	}},
+		target: Schema{[]Field{
+			{"st", []string{"not country", "state", "sttt"}},
+			{"burrow", []string{"hometown", "city"}},
+			{"nationality", []string{"country", "nation", "residency"}},
+		}},
+		expected: map[string]string{
+			"country": "nationality",
+			"state":   "st",
+			"city":    "burrow",
+		}},
+}
+
+func TestMapping(t *testing.T) {
+	t.Parallel()
+	for _, tc := range testcases {
+		if result := Mapping(tc.src, tc.target); !reflect.DeepEqual(result, tc.expected) {
+			t.Errorf("Expected %v but got %v", tc.expected, result)
+		}
+	}
+}
+
+func BenchmarkMapping(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		for _, tc := range testcases {
+			Mapping(tc.src, tc.target)
+		}
+	}
+}