From 1062ec5aa83d7cef647493179bf3f38dc745018a Mon Sep 17 00:00:00 2001
From: David Moles <david.moles@ucop.edu>
Date: Mon, 14 Jan 2019 15:52:39 -0800
Subject: [PATCH] Add Pretty interface

---
 internal/logging/logger.go          | 18 ++++++++++--
 internal/logging/logger_test.go     | 22 +++-----------
 internal/logging/logging_test.go    | 35 +++++++++++++++++++++-
 internal/logging/pretty.go          |  5 ++++
 internal/logging/pretty_test.go     | 45 +++++++++++++++++++++++++++++
 internal/streaming/progress_test.go |  3 ++
 6 files changed, 107 insertions(+), 21 deletions(-)
 create mode 100644 internal/logging/pretty.go
 create mode 100644 internal/logging/pretty_test.go

diff --git a/internal/logging/logger.go b/internal/logging/logger.go
index a9b1d64..6637ecd 100644
--- a/internal/logging/logger.go
+++ b/internal/logging/logger.go
@@ -45,7 +45,8 @@ type infoLogger struct {
 
 // Logger.Info() implementation: log to stderr
 func (l infoLogger) Info(a ...interface{}) {
-	_, err := fmt.Fprintln(l.out, a...)
+	pretty := prettify(a...)
+	_, err := fmt.Fprintln(l.out, pretty...)
 	if err != nil {
 		logFatal(err)
 	}
@@ -53,12 +54,25 @@ func (l infoLogger) Info(a ...interface{}) {
 
 // Logger.Infof() implementation: log to stderr
 func (l infoLogger) Infof(format string, a ...interface{}) {
-	_, err := fmt.Fprintf(l.out, format, a...)
+	pretty := prettify(a...)
+	_, err := fmt.Fprintf(l.out, format, pretty...)
 	if err != nil {
 		logFatal(err)
 	}
 }
 
+func prettify(a ...interface{}) []interface{} {
+	var pretty []interface{}
+	for _, v := range a {
+		if p, ok := v.(Pretty); ok {
+			pretty = append(pretty, p.Pretty())
+		} else {
+			pretty = append(pretty, v)
+		}
+	}
+	return pretty
+}
+
 // ------------------------------
 // terseLogger
 
diff --git a/internal/logging/logger_test.go b/internal/logging/logger_test.go
index 0b0a4f2..0600301 100644
--- a/internal/logging/logger_test.go
+++ b/internal/logging/logger_test.go
@@ -1,8 +1,8 @@
 package logging
 
 import (
-	"strings"
 	"fmt"
+	"strings"
 
 	. "gopkg.in/check.v1"
 )
@@ -43,22 +43,6 @@ func (s *LoggerSuite) logFatal(v ...interface{}) {
 	s.fatals = append(s.fatals, fmt.Sprint(v...))
 }
 
-type StringableWriter interface {
-	Write(p []byte) (n int, err error)
-	String() string
-}
-
-type FailWriter struct {
-
-}
-
-func (f FailWriter) Write(p []byte) (n int, err error) {
-	return 0, fmt.Errorf("failed to write %v", p)
-}
-
-func (f FailWriter) String() string {
-	return "FailWriter{}"
-}
 
 // ------------------------------------------------------------
 // Tests
@@ -153,4 +137,6 @@ func (s *LoggerSuite) TestVerboseFlag(c *C) {
 		}
 		c.Assert(logger.String(), Equals, strExpected)
 	}
-}
\ No newline at end of file
+}
+
+
diff --git a/internal/logging/logging_test.go b/internal/logging/logging_test.go
index c5bd1a3..69a5b5b 100644
--- a/internal/logging/logging_test.go
+++ b/internal/logging/logging_test.go
@@ -1,9 +1,42 @@
 package logging
 
 import (
+	"fmt"
 	"testing"
 
 	. "gopkg.in/check.v1"
 )
 
-func Test(t *testing.T) { TestingT(t) }
\ No newline at end of file
+func Test(t *testing.T) { TestingT(t) }
+
+// ------------------------------------------------------------
+// Helper types
+
+type Prettifiable struct {
+	Val interface{}
+}
+
+func (p Prettifiable) String() string {
+	return fmt.Sprintf("Prettifiable{ Val: %v }", p.Val)
+}
+
+func (p Prettifiable) Pretty() string {
+	return fmt.Sprintf("prettified %v", p.Val)
+}
+
+type StringableWriter interface {
+	Write(p []byte) (n int, err error)
+	String() string
+}
+
+type FailWriter struct {
+
+}
+
+func (f FailWriter) Write(p []byte) (n int, err error) {
+	return 0, fmt.Errorf("failed to write %v", p)
+}
+
+func (f FailWriter) String() string {
+	return "FailWriter{}"
+}
diff --git a/internal/logging/pretty.go b/internal/logging/pretty.go
new file mode 100644
index 0000000..bbc6b63
--- /dev/null
+++ b/internal/logging/pretty.go
@@ -0,0 +1,5 @@
+package logging
+
+type Pretty interface {
+	Pretty() string
+}
diff --git a/internal/logging/pretty_test.go b/internal/logging/pretty_test.go
new file mode 100644
index 0000000..2a70a6c
--- /dev/null
+++ b/internal/logging/pretty_test.go
@@ -0,0 +1,45 @@
+package logging
+
+import (
+	"strings"
+
+	. "gopkg.in/check.v1"
+)
+
+// ------------------------------------------------------------
+// Fixture
+
+type PrettySuite struct {
+	out StringableWriter
+	logger Logger
+}
+
+var _ = Suite(&PrettySuite{})
+
+func (s *PrettySuite) SetUpTest(c *C) {
+	s.out = &strings.Builder{}
+	logger := NewLogger(true).(verboseLogger)
+	logger.out = s.out
+	s.logger = logger
+}
+
+func (s *PrettySuite) TearDownTest(c *C) {
+	s.out = nil
+}
+
+// ------------------------------------------------------------
+// Tests
+
+func (s *PrettySuite) TestPrettyInfo(c *C) {
+	p := Prettifiable{"msg"}
+
+	s.logger.Info(p)
+	c.Assert(s.out.String(), Equals, p.Pretty() + "\n")
+}
+
+func (s *PrettySuite) TestPrettyInfof(c *C) {
+	p := Prettifiable{"msg"}
+
+	s.logger.Infof("Is %v pretty?", p)
+	c.Assert(s.out.String(), Equals, "Is " + p.Pretty() + " pretty?")
+}
diff --git a/internal/streaming/progress_test.go b/internal/streaming/progress_test.go
index 2e08bc6..23e045c 100644
--- a/internal/streaming/progress_test.go
+++ b/internal/streaming/progress_test.go
@@ -58,6 +58,9 @@ func (s *ProgressSuite) TestInfoTo(c *C) {
 	c.Assert(s.logger.Infos[0], Equals, expected)
 }
 
+// ------------------------------------------------------------
+// Helper types
+
 type CapturingLogger struct {
 	Infos   []string
 	Details []string