test.Diff output too verbose

[rade]

Here's an example of a test failure, reported with test.Diff

--- FAIL: TestContainerHostnameRenderer (0.08s)
	container_test.go:82: 
		--- want
		+++ have
		@@ -247,6 +247,45 @@
		 }
		 , }
		 }
		+, }) {
		+   psMap: (*ps.tree)(0xc420c760e0)(({;10.10.10.20;54001: {;10.10.10.20;54001 endpoint {} {} [;192.168.1.1;80] {0001-01-01 00:00:00 +0000 UTC []} {} {} map[] {} {}}, a1b2c3d4e5;<container>: {a1b2c3d4e5;<container> container {} {} [5e4d3c2b1a;<container>] {0001-01-01 00:00:00 +0000 UTC []} {} {} map[] {} {;10.10.10.20;54001: (report.Node) {
...
		+ Children: (report.NodeSet) {}
		+}
		+, }) {
		+           psMap: (*ps.tree)(0xc4208f7b90)(({;10.10.10.20;54002: {;10.10.10.20;54002 endpoint {} {} [;192.168.1.1;80] {0001-01-01 00:00:00 +0000 UTC []} {} {} map[] {} {}}, }
		+) {
		+            count: (int) 1,
		+            hash: (uint64) 14557804364885503053,
		+            key: (string) (len=18) ";10.10.10.20;54002",
		+            value: (report.Node) {
		+             ID: (string) (len=18) ";10.10.10.20;54002",
		+             Topology: (string) (len=8) "endpoint",
		+             Counters: (report.Counters) ({}) {
		+              psMap: (*ps.tree)(0x25e4c00)(({}
		+) {
		+               count: (int) 0,
		+               hash: (uint64) 0,
		+               key: (string) "",
		+               value: (interface {}) <nil>,
		+               children: ([8]*ps.tree) (len=8 cap=8) {
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>)
		+               }
		+              })
		+             },
		+             Sets: (report.Sets) ({}) {
		+              psMap: (*ps.tree)(0x25e4c00)(({}
		+) {
		+               count: (int) 0,
		+               hash: (uint64) 0,
		+               key: (string) "",
		+               value: (interface {}) <nil>,
		+               children: ([8]*ps.tree) (len=8 cap=8) {
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>),
		+                (*ps.tree)(0x25e4c00)(<already shown>)
		+               }
		+              })
		+             },
...

This is showing the internal structures of ps.Maps, which is clearly not desirable.

This used to work much better until 544c349. That set config.ContinueOnMethod = true, which causes structures to be traversed even when they implement Stringer.

[bboreham]

Showing the internal details is desirable in the case that String() has hidden something important. This is difficult to predict in a common library.

I think the real requirement is more like "only print out more if String() looks the same and DeepEqual is false"