Merge pull request #730 from vmware-tanzu/722-missing-key-same-as-null

assert.one_not_null() treats missing keys as null

pkg/yamltemplate/filetests/ytt-library/assert/one_not_null/main.tpltest

@@ -43,7 +43,7 @@ keys_are_specified:
   one_value_not_null_is_ok: #@ assert.one_not_null(["foo", "bar", "baz"]).check(multiple_values_are_not_null())
   non_string_keys_are_ok: #@ assert.one_not_null([0, False, 0.1, "foo"]).check(non_string_keys())
   spec_is_not_a_sequence: #@ assert.try_to(lambda: assert.one_not_null(13).check(one_value_is_not_null()))
-  key_not_found: #@ assert.try_to(lambda: assert.one_not_null(["foo", "not-a-key"]).check(one_value_is_not_null()))
+  key_not_found: #@ assert.one_not_null(["foo", "not-a-key"]).check(one_value_is_not_null())
   too_args: #@ assert.try_to(lambda: assert.one_not_null([], []).check({}))
 
 +++
@@ -72,9 +72,7 @@ keys_are_specified:
   spec_is_not_a_sequence:
   - null
   - 'assert.one_not_null: expected a sequence of keys, but was a ''int'''
-  key_not_found:
-  - null
-  - 'check: "not-a-key" is not present in value'
+  key_not_found: true
   too_args:
   - null
   - 'assert.one_not_null: got 2 arguments, want 1'

pkg/yttlibrary/assert.go

@@ -11,7 +11,6 @@ import (
 	"github.com/k14s/starlark-go/syntax"
 	"github.com/vmware-tanzu/carvel-ytt/pkg/experiments"
 	"github.com/vmware-tanzu/carvel-ytt/pkg/orderedmap"
-	"github.com/vmware-tanzu/carvel-ytt/pkg/spell"
 	"github.com/vmware-tanzu/carvel-ytt/pkg/template/core"
 )
 
@@ -359,8 +358,8 @@ func (m AssertModule) oneNotNullCheck(keys starlark.Sequence) core.StarlarkFunc
 				return nil, fmt.Errorf("check: unexpected error while looking up key %s in dict %s", key, dict)
 			}
 			if !found {
-				hint := m.maybeSuggestKey(key, *dict)
-				return nil, fmt.Errorf("check: %s is not present in value%s", key, hint)
+				// allow schema to catch this (see also https://github.com/vmware-tanzu/carvel-ytt/issues/722)
+				nulls = append(nulls, key.String())
 			}
 			if value == starlark.None {
 				nulls = append(nulls, key.String())
@@ -414,19 +413,6 @@ func (m AssertModule) OneOf(thread *starlark.Thread, f *starlark.Builtin, args s
 	return maxFunc, nil
 }
 
-func (m AssertModule) maybeSuggestKey(given starlark.Value, expected starlark.Dict) string {
-	var keysAsStrings []string
-	for _, k := range expected.Keys() {
-		keysAsStrings = append(keysAsStrings, k.String())
-	}
-	mostSimilarKey := spell.Nearest(given.String(), keysAsStrings)
-	var hint string
-	if mostSimilarKey != "" {
-		hint = fmt.Sprintf(" (did you mean %s?)", mostSimilarKey)
-	}
-	return hint
-}
-
 func (m AssertModule) yamlEncodeDecode(val starlark.Value) (starlark.Value, error) {
 	yaml := yamlModule{}
 	value, err := core.NewStarlarkValue(val).AsGoValue()