Config: Validate Level and EncoderConfig (#791)

This adds validation for Level and EncoderConfig.EncoderTime when building a logger from a zap.Config. Resolves #777 Co-authored-by: Abhinav Gupta <abg@uber.com>

Author: YashishDua

config.go

@@ -21,6 +21,7 @@
 package zap
 
 import (
+"fmt"
 "sort"
 "time"
 
@@ -174,6 +175,10 @@ func (cfg Config) Build(opts ...Option) (*Logger, error) {
 return nil, err
 }
 
+if cfg.Level == (AtomicLevel{}) {
+return nil, fmt.Errorf("missing Level")
+}
+
 log := New(
 zapcore.NewCore(enc, sink, cfg.Level),
 cfg.buildOptions(errSink)...,

config_test.go

@@ -27,6 +27,7 @@ import (
 
 "github.com/stretchr/testify/assert"
 "github.com/stretchr/testify/require"
+"go.uber.org/zap/zapcore"
 )
 
 func TestConfig(t *testing.T) {
@@ -106,3 +107,40 @@ func TestConfigWithInvalidPaths(t *testing.T) {
 })
 }
 }
+
+func TestConfigWithMissingAttributes(t *testing.T) {
+tests := []struct {
+desc string
+cfg Config
+expectErr string
+}{
+{
+desc: "missing level",
+cfg: Config{
+Encoding: "json",
+},
+expectErr: "missing Level",
+},
+{
+desc: "missing encoder time in encoder config",
+cfg: Config{
+Level: NewAtomicLevelAt(zapcore.InfoLevel),
+Encoding: "json",
+EncoderConfig: zapcore.EncoderConfig{
+MessageKey: "msg",
+TimeKey: "ts",
+},
+},
+expectErr: "missing EncodeTime in EncoderConfig",
+},
+}
+
+for _, tt := range tests {
+t.Run(tt.desc, func(t *testing.T) {
+cfg := tt.cfg
+_, err := cfg.Build()
+require.Error(t, err)
+assert.Equal(t, tt.expectErr, err.Error())
+})
+}
+}

encoder.go

@@ -62,6 +62,10 @@ func RegisterEncoder(name string, constructor func(zapcore.EncoderConfig) (zapco
 }
 
 func newEncoder(name string, encoderConfig zapcore.EncoderConfig) (zapcore.Encoder, error) {
+if encoderConfig.TimeKey != "" && encoderConfig.EncodeTime == nil {
+return nil, fmt.Errorf("missing EncodeTime in EncoderConfig")
+}
+
 _encoderMutex.RLock()
 defer _encoderMutex.RUnlock()
 if name == "" {