refactor: focus around Render/Compact/Pretty/NewWith functions

This is yet another drastic refactor of public API and concepts.
Hopefully the last one, as I'm now fairly happy with things.

json_test.go

@@ -23,38 +23,22 @@ func (mjm *mockJSONMarshaler) MarshalJSON() ([]byte, error) {
 
 func TestJSON_Render(t *testing.T) {
 	tests := []struct {
-		name      string
-		pretty    bool
-		prefix    string
-		indent    string
-		value     interface{}
-		want      string
-		wantErr   string
-		wantErrIs []error
+		name       string
+		prefix     string
+		indent     string
+		value      any
+		want       string
+		wantPretty string
+		wantErr    string
+		wantErrIs  []error
 	}{
 		{
-			name:   "simple object without pretty",
-			pretty: false,
-			value:  map[string]int{"age": 30},
-			want:   "{\"age\":30}\n",
+			name:  "simple object",
+			value: map[string]int{"age": 30},
+			want:  "{\"age\":30}\n",
 		},
 		{
-			name:   "simple object with pretty",
-			pretty: true,
-			value:  map[string]int{"age": 30},
-			want:   "{\n  \"age\": 30\n}\n",
-		},
-		{
-			name:   "pretty with prefix and indent",
-			pretty: true,
-			prefix: "// ",
-			indent: "\t",
-			value:  map[string]int{"age": 30},
-			want:   "{\n// \t\"age\": 30\n// }\n",
-		},
-		{
-			name:   "prefix and indent without pretty",
-			pretty: false,
+			name:   "ignores prefix and indent",
 			prefix: "// ",
 			indent: "\t",
 			value:  map[string]int{"age": 30},
@@ -72,7 +56,6 @@ func TestJSON_Render(t *testing.T) {
 		},
 		{
 			name:      "invalid value",
-			pretty:    false,
 			value:     make(chan int),
 			wantErr:   "render: failed: json: unsupported type: chan int",
 			wantErrIs: []error{Err, ErrFailed},
@@ -81,7 +64,6 @@ func TestJSON_Render(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			j := &JSON{
-				Pretty: tt.pretty,
 				Prefix: tt.prefix,
 				Indent: tt.indent,
 			}
@@ -105,3 +87,76 @@ func TestJSON_Render(t *testing.T) {
 		})
 	}
 }
+
+func TestJSON_RenderPretty(t *testing.T) {
+	tests := []struct {
+		name       string
+		prefix     string
+		indent     string
+		value      any
+		want       string
+		wantPretty string
+		wantErr    string
+		wantErrIs  []error
+	}{
+		{
+			name:  "simple object",
+			value: map[string]int{"age": 30},
+			want:  "{\n  \"age\": 30\n}\n",
+		},
+		{
+			name:   "uses prefix and indent",
+			prefix: "// ",
+			indent: "\t",
+			value:  map[string]int{"age": 30},
+			want:   "{\n// \t\"age\": 30\n// }\n",
+		},
+		{
+			name:  "implements json.Marshaler",
+			value: &mockJSONMarshaler{data: []byte(`{"age":30}`)},
+			want:  "{\n  \"age\": 30\n}\n",
+		},
+		{
+			name:      "error from json.Marshaler",
+			value:     &mockJSONMarshaler{err: errors.New("marshal error!!1")},
+			wantErrIs: []error{Err, ErrFailed},
+		},
+		{
+			name:      "invalid value",
+			value:     make(chan int),
+			wantErr:   "render: failed: json: unsupported type: chan int",
+			wantErrIs: []error{Err, ErrFailed},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			j := &JSON{
+				Prefix: tt.prefix,
+				Indent: tt.indent,
+			}
+			var buf bytes.Buffer
+
+			err := j.RenderPretty(&buf, tt.value)
+			got := buf.String()
+
+			if tt.wantErr != "" {
+				require.Error(t, err)
+				assert.EqualError(t, err, tt.wantErr)
+			}
+			for _, e := range tt.wantErrIs {
+				assert.ErrorIs(t, err, e)
+			}
+
+			if tt.wantErr == "" && len(tt.wantErrIs) == 0 {
+				require.NoError(t, err)
+				assert.Equal(t, tt.want, got)
+			}
+		})
+	}
+}
+
+func TestJSON_Formats(t *testing.T) {
+	h := &JSON{}
+
+	assert.Equal(t, []string{"json"}, h.Formats())
+}