Merge pull request #182 from grafana/or-null-case

gocode: Generate correct go types in unions will `null`

assignable.go

@@ -87,11 +87,22 @@ func assignable(sch cue.Value, T interface{}) error {
 	var check, checkstruct, checklist, checkscalar checkfn
 
 	check = func(gval, sval cue.Value, p cue.Path) {
-		// At least for now, we have to deal with these unhelpful *null
-		// appearing in the encoding of pointer types.
-		gval = stripLeadNull(gval)
-
 		sk, gk := sval.IncompleteKind(), gval.IncompleteKind()
+		schemaHadNull, goHadNull := sk&cue.NullKind != 0, gk&cue.NullKind != 0
+		sk &^= cue.NullKind
+		gk &^= cue.NullKind
+
+		ogval := gval
+		if goHadNull {
+			// At least for now, we have to deal with these unhelpful *null
+			// appearing in the encoding of pointer types.
+			//
+			// We can't do the same for the schema side, because this null stripper
+			// relies on the fact that all actual Go type declarations will come across
+			// as a single value, without any disjunctions.
+			gval = stripLeadNull(gval)
+		}
+
 		// strict equality _might_ be too restrictive? But it's better to start there
 		if sk != gk && gk != cue.TopKind {
 			errs[p.String()] = fmt.Errorf("%s: is kind %s in schema, but kind %s in Go type", p, sk, gk)
@@ -104,10 +115,12 @@ func assignable(sch cue.Value, T interface{}) error {
 		switch sk {
 		case cue.ListKind:
 			checklist(gval, sval, p)
-		case cue.FloatKind, cue.IntKind, cue.StringKind, cue.BytesKind, cue.BoolKind:
-			checkscalar(gval, sval, p)
-		case cue.NumberKind:
-			checkscalar(gval, sval, p)
+		case cue.FloatKind, cue.IntKind, cue.StringKind, cue.BytesKind, cue.BoolKind, cue.NumberKind:
+			if schemaHadNull {
+				checkscalar(ogval, sval, p)
+			} else {
+				checkscalar(gval, sval, p)
+			}
 		case cue.StructKind:
 			checkstruct(gval, sval, p)
 		case cue.NullKind:
@@ -270,7 +283,7 @@ func assignable(sch cue.Value, T interface{}) error {
 func stripLeadNull(v cue.Value) cue.Value {
 	if op, vals := v.Expr(); op == cue.OrOp {
 		// Walk over the vals, because there may be more than one null (e.g. omitempty +
-		// slice/map type)
+		// slice/map type).
 		for i := 0; i < len(vals); i++ {
 			if vals[i].Null() != nil {
 				return vals[i]

assignable_test.go

@@ -352,6 +352,22 @@ func TestAssignable(t *testing.T) {
 			}
 			`, strconv.IntSize, strconv.IntSize),
 		},
+		"or-null": {
+			T: &struct {
+				Both   *string `json:"both,omitempty"`
+				NoOmit *string `json:"noOmit"`
+				// This case is the ugly ambiguous one - is the user saying that an empty string
+				// should be serialized as an absent field, but a nil pointer be serialized as
+				// null? WAAAAAAAT
+				Optional *string `json:"optional"`
+			}{},
+			cue: `typ: {
+				both: string | null
+				noOmit: string | null
+				optional?: string | null
+			}
+			`,
+		},
 	}
 
 	for name, tst := range tt {

encoding/gocode/gocode_test.go

@@ -6,6 +6,7 @@ import (
 
 	"cuelang.org/go/cue/cuecontext"
 	copenapi "cuelang.org/go/encoding/openapi"
+
 	"github.com/grafana/thema"
 	"github.com/grafana/thema/encoding/openapi"
 	"github.com/grafana/thema/internal/txtartest/bindlin"

go.mod

@@ -5,7 +5,7 @@ go 1.19
 // contains openapi encoder fixes. commented out because impact for
 // most thema CLI uses is minimal, and others (e.g. grafana/grafana)
 // can hoist this themselves if they need it
-replace cuelang.org/go => github.com/sdboyer/cue v0.5.0-beta.2.0.20221218111347-341999f48bdb
+replace cuelang.org/go => github.com/sdboyer/cue v0.5.0-beta.2.0.20230712135403-bdc4772ae055
 
 require (
 	cuelang.org/go v0.5.0

go.sum

@@ -227,8 +227,8 @@ github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/ryanuber/columnize v2.1.0+incompatible/go.mod h1:sm1tb6uqfes/u+d4ooFouqFdy9/2g9QGwK3SQygK0Ts=
 github.com/schollz/closestmatch v2.1.0+incompatible/go.mod h1:RtP1ddjLong6gTkbtmuhtR2uUrrJOpYzYRvbcPAid+g=
-github.com/sdboyer/cue v0.5.0-beta.2.0.20221218111347-341999f48bdb h1:X6XJsprVDQnlG4vT5TVb+cRlGMU78L/IKej8Q6SDFGY=
-github.com/sdboyer/cue v0.5.0-beta.2.0.20221218111347-341999f48bdb/go.mod h1:okjJBHFQFer+a41sAe2SaGm1glWS8oEb6CmJvn5Zdws=
+github.com/sdboyer/cue v0.5.0-beta.2.0.20230712135403-bdc4772ae055 h1:ilCOPMIGucstzXKgCVzAT8g6tu+Ejyk0J1HhXZN2xm0=
+github.com/sdboyer/cue v0.5.0-beta.2.0.20230712135403-bdc4772ae055/go.mod h1:okjJBHFQFer+a41sAe2SaGm1glWS8oEb6CmJvn5Zdws=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
 github.com/sergi/go-diff v1.3.1 h1:xkr+Oxo4BOQKmkn/B9eMK0g5Kg/983T9DqqPHwYqD+8=
 github.com/sergi/go-diff v1.3.1/go.mod h1:aMJSSKb2lpPvRNec0+w3fl7LP9IOFzdc9Pa4NFbPK1I=