Add tests for custom type that panics in Stringer.

spew/dump_test.go

@@ -50,6 +50,7 @@ base test element are also tested to ensure proper indirection across all types.
 - Struct that is circular through self referencing
 - Structs that are circular through cross referencing
 - Structs that are indirectly circular
+- Type that panics in its Stringer interface
 */
 
 package spew_test
@@ -748,6 +749,21 @@ func addCircularDumpTests() {
 	addDumpTest(&pv3, "(**"+v3t+")("+pv3Addr+"->"+v3Addr+")("+v3s2+")\n")
 }
 
+func addPanicDumpTests() {
+	// Type that panics in its Stringer interface.
+	v := panicer(127)
+	nv := (*panicer)(nil)
+	pv := &v
+	vAddr := fmt.Sprintf("%p", pv)
+	pvAddr := fmt.Sprintf("%p", &pv)
+	vt := "spew_test.panicer"
+	vs := "(PANIC=test panic)127"
+	addDumpTest(v, "("+vt+") "+vs+"\n")
+	addDumpTest(pv, "(*"+vt+")("+vAddr+")("+vs+")\n")
+	addDumpTest(&pv, "(**"+vt+")("+pvAddr+"->"+vAddr+")("+vs+")\n")
+	addDumpTest(nv, "(*"+vt+")(<nil>)\n")
+}
+
 // TestDump executes all of the tests described by dumpTests.
 func TestDump(t *testing.T) {
 	// Setup tests.
@@ -767,6 +783,7 @@ func TestDump(t *testing.T) {
 	addChanDumpTests()
 	addFuncDumpTests()
 	addCircularDumpTests()
+	addPanicDumpTests()
 
 	t.Logf("Running %d tests", len(dumpTests))
 	for i, test := range dumpTests {

spew/format_test.go

@@ -50,6 +50,7 @@ base test element are also tested to ensure proper indirection across all types.
 - Struct that is circular through self referencing
 - Structs that are circular through cross referencing
 - Structs that are indirectly circular
+- Type that panics in its Stringer interface
 */
 
 package spew_test
@@ -1222,6 +1223,33 @@ func addCircularFormatterTests() {
 	addFormatterTest("%#+v", &pv3, "(**"+v3t+")("+pv3Addr+"->"+v3Addr+")"+v3s8)
 }
 
+func addPanicFormatterTests() {
+	// Type that panics in its Stringer interface.
+	v := panicer(127)
+	nv := (*panicer)(nil)
+	pv := &v
+	vAddr := fmt.Sprintf("%p", pv)
+	pvAddr := fmt.Sprintf("%p", &pv)
+	vt := "spew_test.panicer"
+	vs := "(PANIC=test panic)127"
+	addFormatterTest("%v", v, vs)
+	addFormatterTest("%v", pv, "<*>"+vs)
+	addFormatterTest("%v", &pv, "<**>"+vs)
+	addFormatterTest("%v", nv, "<nil>")
+	addFormatterTest("%+v", v, vs)
+	addFormatterTest("%+v", pv, "<*>("+vAddr+")"+vs)
+	addFormatterTest("%+v", &pv, "<**>("+pvAddr+"->"+vAddr+")"+vs)
+	addFormatterTest("%+v", nv, "<nil>")
+	addFormatterTest("%#v", v, "("+vt+")"+vs)
+	addFormatterTest("%#v", pv, "(*"+vt+")"+vs)
+	addFormatterTest("%#v", &pv, "(**"+vt+")"+vs)
+	addFormatterTest("%#v", nv, "(*"+vt+")"+"<nil>")
+	addFormatterTest("%#+v", v, "("+vt+")"+vs)
+	addFormatterTest("%#+v", pv, "(*"+vt+")("+vAddr+")"+vs)
+	addFormatterTest("%#+v", &pv, "(**"+vt+")("+pvAddr+"->"+vAddr+")"+vs)
+	addFormatterTest("%#+v", nv, "(*"+vt+")"+"<nil>")
+}
+
 // TestFormatter executes all of the tests described by formatterTests.
 func TestFormatter(t *testing.T) {
 	// Setup tests.
@@ -1241,6 +1269,7 @@ func TestFormatter(t *testing.T) {
 	addChanFormatterTests()
 	addFuncFormatterTests()
 	addCircularFormatterTests()
+	addPanicFormatterTests()
 
 	t.Logf("Running %d tests", len(formatterTests))
 	for i, test := range formatterTests {

spew/spew_test.go

@@ -50,6 +50,14 @@ func testFailed(result string, wants []string) bool {
 	return true
 }
 
+// panicer is used to intentionally cause a panic for testing spew properly
+// handles them
+type panicer int
+
+func (p panicer) String() string {
+	panic("test panic")
+}
+
 // spewFunc is used to identify which public function of the spew package or
 // ConfigState a test applies to.
 type spewFunc int