encoding/jsonschema: implement "not"

This change implements the "not" keyword using `matchN`.
No test regressions were encountered when updating the external test data.

One regression was encountered when updating the regular
test data, and filed as a comment under issue #3422.
This required updating the test data to get the test to pass.

Signed-off-by: Roger Peppe <[email protected]>
Change-Id: Ib2537af7424895843eebc1b915bc643894637afa
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1200530
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>

cue.mod/pkg/github.com/SchemaStore/schemastore/src/schemas/json/github-workflow.cue

@@ -624,15 +624,33 @@ import "strings"
 
 	#path: #globs
 
-	#ref: null | {
+	#ref: matchN(1, [matchN(3, [matchN(0, [null | bool | number | string | [...] | {
+		branches!:          _
+		"branches-ignore"!: _
+		...
+	}]) & {
+		...
+	}, matchN(0, [null | bool | number | string | [...] | {
+		tags!:          _
+		"tags-ignore"!: _
+		...
+	}]) & {
+		...
+	}, matchN(0, [null | bool | number | string | [...] | {
+		paths!:          _
+		"paths-ignore"!: _
+		...
+	}]) & {
+		...
+	}]), null]) & (null | {
 		branches?:          #branch
 		"branches-ignore"?: #branch
 		tags?:              #branch
 		"tags-ignore"?:     #branch
 		paths?:             #path
 		"paths-ignore"?:    #path
 		...
-	}
+	})
 
 	#shell: matchN(>=1, [string, "bash" | "pwsh" | "python" | "sh" | "cmd" | "powershell"])
 

encoding/jsonschema/constraints.go

@@ -88,6 +88,7 @@ var constraints = []*constraint{
 	p2("minLength", constraintMinLength),
 	p3("minimum", constraintMinimum),
 	p2("multipleOf", constraintMultipleOf),
+	p3("not", constraintNot),
 	p3("oneOf", constraintOneOf),
 	p2("nullable", constraintNullable),
 	p2("pattern", constraintPattern),

encoding/jsonschema/constraints_combinator.go

@@ -136,3 +136,15 @@ func constraintOneOf(key string, n cue.Value, s *state) {
 	// TODO: oneOf({a:x}, {b:y}, ..., not(anyOf({a:x}, {b:y}, ...))),
 	// can be translated to {} | {a:x}, {b:y}, ...
 }
+
+func constraintNot(key string, n cue.Value, s *state) {
+	subSchema := s.schema(n)
+	s.all.add(n, ast.NewCall(
+		ast.NewIdent("matchN"),
+		&ast.BasicLit{
+			Kind:  token.INT,
+			Value: "0",
+		},
+		ast.NewList(subSchema),
+	))
+}

encoding/jsonschema/external_teststats.txt

@@ -1,10 +1,10 @@
 # Generated by teststats. DO NOT EDIT
 v2:
-	schema extract (pass / total): 975 / 1637 = 59.6%
-	tests (pass / total): 3140 / 7175 = 43.8%
-	tests on extracted schemas (pass / total): 3140 / 3546 = 88.6%
+	schema extract (pass / total): 1015 / 1637 = 62.0%
+	tests (pass / total): 3308 / 7175 = 46.1%
+	tests on extracted schemas (pass / total): 3308 / 3722 = 88.9%
 
 v3:
-	schema extract (pass / total): 967 / 1637 = 59.1%
-	tests (pass / total): 3074 / 7175 = 42.8%
-	tests on extracted schemas (pass / total): 3074 / 3538 = 86.9%
+	schema extract (pass / total): 1003 / 1637 = 61.3%
+	tests (pass / total): 3214 / 7175 = 44.8%
+	tests on extracted schemas (pass / total): 3214 / 3678 = 87.4%