klogr: report missing values with "(MISSING)"

klogr had a special value for a missing value in a key/value pair, so the
intention probably was to use that as replacement, the same way as klog does
it. But because of a bug in the code which removed duplicates, it treated a
missing value like nil. Now the behavior is consistent with klog.

internal/serialize/keyvalues.go

@@ -36,7 +36,11 @@ func TrimDuplicates(kvLists ...[]interface{}) [][]interface{} {
 		// initialise this output slice
 		outs[i] = []interface{}{}
 		// obtain a reference to the kvList we are processing
+		// and make sure it has an even number of entries
 		kvList := kvLists[i]
+		if len(kvList)%2 != 0 {
+			kvList = append(kvList, missingValue)
+		}
 
 		// start iterating at len(kvList) - 2 (i.e. the 2nd last item) for
 		// slices that have an even number of elements.

klogr/klogr_test.go

@@ -113,9 +113,9 @@ func testOutput(t *testing.T, format string) {
 			klogr:         new(),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue", "akey2"},
-			expectedOutput: ` "msg"="test"  "akey"="avalue" "akey2"=null
+			expectedOutput: ` "msg"="test"  "akey"="avalue" "akey2"="(MISSING)"
 `,
-			expectedKlogOutput: `"test" akey="avalue" akey2=<nil>
+			expectedKlogOutput: `"test" akey="avalue" akey2="(MISSING)"
 `,
 		},
 		"should correctly html characters": {
@@ -131,9 +131,9 @@ func testOutput(t *testing.T, format string) {
 			klogr:         new().WithValues("basekey1", "basevar1", "basekey2"),
 			text:          "test",
 			keysAndValues: []interface{}{"akey", "avalue", "akey2"},
-			expectedOutput: ` "msg"="test" "basekey1"="basevar1" "basekey2"=null "akey"="avalue" "akey2"=null
+			expectedOutput: ` "msg"="test" "basekey1"="basevar1" "basekey2"="(MISSING)" "akey"="avalue" "akey2"="(MISSING)"
 `,
-			expectedKlogOutput: `"test" basekey1="basevar1" basekey2=<nil> akey="avalue" akey2=<nil>
+			expectedKlogOutput: `"test" basekey1="basevar1" basekey2="(MISSING)" akey="avalue" akey2="(MISSING)"
 `,
 		},
 		"should correctly print regular error types": {

test/output_test.go

@@ -42,15 +42,9 @@ func TestKlogrOutput(t *testing.T) {
 		`I output.go:<LINE>] "test" keyWithoutValue="(MISSING)"
 I output.go:<LINE>] "test" keyWithoutValue="(MISSING)" anotherKeyWithoutValue="(MISSING)"
 I output.go:<LINE>] "test" keyWithoutValue="(MISSING)"
-`: `I output.go:<LINE>] "test" keyWithoutValue=<nil>
+`: `I output.go:<LINE>] "test" keyWithoutValue="(MISSING)"
 I output.go:<LINE>] "test" keyWithoutValue="anotherKeyWithoutValue"
-I output.go:<LINE>] "test" keyWithoutValue=<nil>
-`,
-		`I output.go:<LINE>] "test" akey="avalue" akey2="(MISSING)"
-`: `I output.go:<LINE>] "test" akey="avalue" akey2=<nil>
-`,
-		`I output.go:<LINE>] "test" basekey1="basevar1" basekey2="(MISSING)" akey="avalue" akey2="(MISSING)"
-`: `I output.go:<LINE>] "test" basekey1="basevar1" basekey2=<nil> akey="avalue" akey2=<nil>
+I output.go:<LINE>] "test" keyWithoutValue="(MISSING)"
 `,
 	}
 	Output(t, OutputConfig{