log_writer_test.go

package peanut_test

import (
	"bytes"
	"io/ioutil"
	"log"
	"os"
	"strings"

	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"

	"github.com/jimsmart/peanut"
)

var _ = Describe("LogWriter", func() {

	newFn := func() (peanut.Writer, *bytes.Buffer) {
		buf := &bytes.Buffer{}
		w := &peanut.LogWriter{
			Logger:  log.New(buf, "", 0),
			Verbose: true,
		}
		return w, buf
	}

	It("should write the correct text when sequential structs are written", func() {
		w, buf := newFn()

		testWritesAndCloseSequential(w)

		expectedOutput := "<Foo> foo_string: test 1 foo_int: 1\n" +
			"<Foo> foo_string: test 2 foo_int: 2\n" +
			"<Foo> foo_string: test 3 foo_int: 3\n" +
			"<Bar> bar_int: 1 bar_string: test 1\n" +
			"<Bar> bar_int: 2 bar_string: test 2\n" +
			"<Bar> bar_int: 3 bar_string: test 3\n" +
			"<Baz> baz_string: test 1 baz_bool: true baz_float32: 1.234 baz_float64: 9.876 baz_int: -12345 baz_int8: -8 baz_int16: -16 baz_int32: -32 baz_int64: -64 baz_uint: 12345 baz_uint8: 8 baz_uint16: 16 baz_uint32: 32 baz_uint64: 64\n" +
			"<Qux> -\n" +
			"<Qux> -\n" +
			"<Qux> -\n" +
			"Called LogWriter.Close\n" +
			"Called LogWriter.Cancel\n"

		output := string(buf.Bytes())
		// fmt.Println(output)
		Expect(output).To(Equal(expectedOutput))
	})

	It("should write the correct text when interleaved structs are written", func() {
		w, buf := newFn()

		testWritesAndCloseInterleaved(w)

		expectedOutput := "<Foo> foo_string: test 1 foo_int: 1\n" +
			"<Bar> bar_int: 1 bar_string: test 1\n" +
			"<Qux> -\n" +
			"<Foo> foo_string: test 2 foo_int: 2\n" +
			"<Bar> bar_int: 2 bar_string: test 2\n" +
			"<Qux> -\n" +
			"<Foo> foo_string: test 3 foo_int: 3\n" +
			"<Bar> bar_int: 3 bar_string: test 3\n" +
			"<Qux> -\n" +
			"<Baz> baz_string: test 1 baz_bool: true baz_float32: 1.234 baz_float64: 9.876 baz_int: -12345 baz_int8: -8 baz_int16: -16 baz_int32: -32 baz_int64: -64 baz_uint: 12345 baz_uint8: 8 baz_uint16: 16 baz_uint32: 32 baz_uint64: 64\n" +
			"Called LogWriter.Close\n"

		output := string(buf.Bytes())
		// fmt.Println(output)
		Expect(output).To(Equal(expectedOutput))
	})

	It("should write the correct text when structs are written and cancel is called", func() {
		w, buf := newFn()

		testWritesAndCancel(w)

		expectedOutput := "<Foo> foo_string: test 1 foo_int: 1\n" +
			"<Bar> bar_int: 1 bar_string: test 1\n" +
			"Called LogWriter.Cancel\n" +
			"Called LogWriter.Close\n"

		output := string(buf.Bytes())
		Expect(output).To(Equal(expectedOutput))
	})

	It("should not return any errors when used with its default config", func() {
		w := &peanut.LogWriter{}

		// Temporarily replace Stderr, to capture log output.
		// See https://stackoverflow.com/questions/25609734/testing-stdout-with-go-and-ginkgo
		pr, pw, _ := os.Pipe()
		tmp := os.Stderr
		defer func() {
			os.Stderr = tmp
		}()
		os.Stderr = pw
		go func() {
			// Run our tests.
			testWritesAndCloseSequential(w)
			pw.Close()
		}()
		stdout, _ := ioutil.ReadAll(pr)

		// Output looks like:
		// 2021/04/18 20:35:43 <Foo> foo_string: test 1 foo_int: 1
		// 2021/04/18 20:35:43 <Foo> foo_string: test 2 foo_int: 2
		// 2021/04/18 20:35:43 <Foo> foo_string: test 3 foo_int: 3
		// 2021/04/18 20:35:43 <Bar> bar_int: 1 bar_string: test 1
		// 2021/04/18 20:35:43 <Bar> bar_int: 2 bar_string: test 2
		// 2021/04/18 20:35:43 <Bar> bar_int: 3 bar_string: test 3
		// 2021/04/18 20:35:43 <Baz> baz_string: test 1 baz_bool: true baz_float32: 1.234 baz_float64: 9.876 baz_int: -12345 baz_int8: -8 baz_int16: -16 baz_int32: -32 baz_int64: -64 baz_uint: 12345 baz_uint8: 8 baz_uint16: 16 baz_uint32: 32 baz_uint64: 64"

		lines := strings.Split(string(stdout), "\n")
		for _, x := range lines {
			// fmt.Println(x)
			if len(x) > 0 {
				Expect(x).To(MatchRegexp(`^\d{4}\/\d{2}\/\d{2} \d{2}:\d{2}:\d{2} <[A-Z][a-z]*> [a-z\-]`))
			}
		}
	})

	Context("when given a struct with an unsupported field type", func() {

		It("should return an error with an informative message", func() {
			w := &peanut.LogWriter{}

			testWriteBadType(w)
			// TODO(js) Do we need further checks, e.g. file not exists ...?
		})
	})

})