kversion: remove patch from VersionGuess when we cannot know it

Pre 1.0.0, patch numbers actually went v0.9.0.1; we already did not
include the final .1. Post 1.0.0, we cannot know patch numbers, so let's
exclude them.

Also changes from saying "tip" to "at least <final verison kversion
knows about>", so a user can know how out of date their kversion / kgo
is.

Also moves the cmp map to the top to only allocate it once. We either
clear it every loop, or it is non-empty which results in the "under"
case which returns within that loop.

pkg/kversion/kversion.go

@@ -119,6 +119,7 @@ func (vs *Versions) Equal(other *Versions) bool {
 // more verbose strings.
 func (vs *Versions) VersionGuess() string {
  var last string
+ cmp := make(map[int16]int16, len(maxTip))
  for _, comparison := range []struct {
  cmp []int16
  name string
@@ -131,26 +132,24 @@ func (vs *Versions) VersionGuess() string {
  {max0101, "v0.10.1"},
  {max0102, "v0.10.2"},
  {max0110, "v0.11.0"},
- {max100, "v1.0.0"},
- {max110, "v1.1.0"},
- {max200, "v2.0.0"},
- {max210, "v2.1.0"},
- {max220, "v2.2.0"},
- {max230, "v2.3.0"},
- {max240, "v2.4.0"},
- {max250, "v2.5.0"},
- {max260, "v2.6.0"},
- {max270, "v2.7.0"},
- {maxTip, "tip"},
+ {max100, "v1.0"},
+ {max110, "v1.1"},
+ {max200, "v2.0"},
+ {max210, "v2.1"},
+ {max220, "v2.2"},
+ {max230, "v2.3"},
+ {max240, "v2.4"},
+ {max250, "v2.5"},
+ {max260, "v2.6"},
+ {max270, "v2.7"},
  } {
 
- var under, equal, over bool
-
- cmp := make(map[int16]int16, len(comparison.cmp))
  for k, v := range comparison.cmp {
  cmp[int16(k)] = v
  }
 
+ var under, equal, over bool
+
  for k, v := range vs.k2v {
  cmpv, has := cmp[int16(k)]
  if has {
@@ -215,7 +214,7 @@ func (vs *Versions) VersionGuess() string {
  // is no default case.
  }
 
- return last // we never reach this because we always return above
+ return "at least " + last
 }
 
 // Returns a string representation of the versions; the format may change.

pkg/kversion/kversion_test.go

@@ -49,10 +49,19 @@ func TestVersionGuess(t *testing.T) {
  {
  v := V2_7_0()
  v.SetMaxKeyVersion(int16(len(v.k2v)+1), -1)
- if got, exp := v.VersionGuess(), "v2.7.0"; got != exp {
+ if got, exp := v.VersionGuess(), "v2.7"; got != exp {
  t.Errorf("got %s != exp %s without modifications", got, exp)
  }
  }
+
+ {
+ v := Tip()
+ v.SetMaxKeyVersion(0, 999)
+ if got, exp := v.VersionGuess(), "at least v2.7"; got != exp {
+ t.Errorf("got %s != exp %s without modifications", got, exp)
+ }
+ }
+
 }
 
 func TestEqual(t *testing.T) {