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Adding alternative implementation of Unmarshal which allows supplying
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of opts which can be used to modify the unmarshalling behaviour,
such as ignoring undefined attributes (#212)
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@bendbennett
bendbennett committed Jul 27, 2022
1 parent a325d5b commit cff7cc2
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Showing 4 changed files with 119 additions and 21 deletions.
12 changes: 12 additions & 0 deletions tfprotov5/state.go
View file
Expand Up @@ -77,3 +77,15 @@ func (s RawState) Unmarshal(typ tftypes.Type) (tftypes.Value, error) {
}
return tftypes.Value{}, ErrUnknownRawStateType
}

// UnmarshalWithOpts is identical to Unmarshal but also accepts a tftypes.UnmarshalOpts which contains
// options that can be used to modify the behaviour when unmarshalling JSON or Flatmap.
func (s RawState) UnmarshalWithOpts(typ tftypes.Type, opts tftypes.UnmarshalOpts) (tftypes.Value, error) {
if s.JSON != nil {
return tftypes.ValueFromJSONWithOpts(s.JSON, typ, opts.JsonOpts) //nolint:staticcheck
}
if s.Flatmap != nil {
return tftypes.Value{}, fmt.Errorf("flatmap states cannot be unmarshaled, only states written by Terraform 0.12 and higher can be unmarshaled")
}
return tftypes.Value{}, ErrUnknownRawStateType
}
12 changes: 12 additions & 0 deletions tfprotov6/state.go
View file
Expand Up @@ -77,3 +77,15 @@ func (s RawState) Unmarshal(typ tftypes.Type) (tftypes.Value, error) {
}
return tftypes.Value{}, ErrUnknownRawStateType
}

// UnmarshalWithOpts is identical to Unmarshal but also accepts a tftypes.UnmarshalOpts which contains
// options that can be used to modify the behaviour when unmarshalling JSON or Flatmap.
func (s RawState) UnmarshalWithOpts(typ tftypes.Type, opts tftypes.UnmarshalOpts) (tftypes.Value, error) {
if s.JSON != nil {
return tftypes.ValueFromJSONWithOpts(s.JSON, typ, opts.JsonOpts) //nolint:staticcheck
}
if s.Flatmap != nil {
return tftypes.Value{}, fmt.Errorf("flatmap states cannot be unmarshaled, only states written by Terraform 0.12 and higher can be unmarshaled")
}
return tftypes.Value{}, ErrUnknownRawStateType
}
72 changes: 51 additions & 21 deletions tftypes/value_json.go
View file
Expand Up @@ -16,7 +16,28 @@ import (
// terraform-plugin-go. Third parties should not use it, and its behavior is
// not covered under the API compatibility guarantees. Don't use this.
func ValueFromJSON(data []byte, typ Type) (Value, error) {
return jsonUnmarshal(data, typ, NewAttributePath())
return jsonUnmarshal(data, typ, NewAttributePath(), JSONOpts{})
}

// UnmarshalOpts contains options that can be used to modify the behaviour when
// unmarshalling. Currently, this only contains a struct for opts for JSON but
// could have a field for Flatmap in the future.
type UnmarshalOpts struct {
JsonOpts JSONOpts
}

// JSONOpts contains options that can be used to modify the behaviour when
// unmarshalling JSON.
type JSONOpts struct {
IgnoreUndefinedAttributes bool
}

// ValueFromJSONWithOpts is identical to ValueFromJSON with the exception that it
// accepts JSONOpts which can be used to modify the unmarshalling behaviour, such
// as ignoring undefined attributes, for instance. This can occur when the JSON
// being unmarshalled does not have a corresponding attribute in the schema.
func ValueFromJSONWithOpts(data []byte, typ Type, opts JSONOpts) (Value, error) {
return jsonUnmarshal(data, typ, NewAttributePath(), opts)
}

func jsonByteDecoder(buf []byte) *json.Decoder {
Expand All @@ -26,7 +47,7 @@ func jsonByteDecoder(buf []byte) *json.Decoder {
return dec
}

func jsonUnmarshal(buf []byte, typ Type, p *AttributePath) (Value, error) {
func jsonUnmarshal(buf []byte, typ Type, p *AttributePath, opts JSONOpts) (Value, error) {
dec := jsonByteDecoder(buf)

tok, err := dec.Token()
Expand All @@ -46,18 +67,17 @@ func jsonUnmarshal(buf []byte, typ Type, p *AttributePath) (Value, error) {
case typ.Is(Bool):
return jsonUnmarshalBool(buf, typ, p)
case typ.Is(DynamicPseudoType):
return jsonUnmarshalDynamicPseudoType(buf, typ, p)
return jsonUnmarshalDynamicPseudoType(buf, typ, p, opts)
case typ.Is(List{}):
return jsonUnmarshalList(buf, typ.(List).ElementType, p)
return jsonUnmarshalList(buf, typ.(List).ElementType, p, opts)
case typ.Is(Set{}):
return jsonUnmarshalSet(buf, typ.(Set).ElementType, p)

return jsonUnmarshalSet(buf, typ.(Set).ElementType, p, opts)
case typ.Is(Map{}):
return jsonUnmarshalMap(buf, typ.(Map).ElementType, p)
return jsonUnmarshalMap(buf, typ.(Map).ElementType, p, opts)
case typ.Is(Tuple{}):
return jsonUnmarshalTuple(buf, typ.(Tuple).ElementTypes, p)
return jsonUnmarshalTuple(buf, typ.(Tuple).ElementTypes, p, opts)
case typ.Is(Object{}):
return jsonUnmarshalObject(buf, typ.(Object).AttributeTypes, p)
return jsonUnmarshalObject(buf, typ.(Object).AttributeTypes, p, opts)
}
return Value{}, p.NewErrorf("unknown type %s", typ)
}
Expand Down Expand Up @@ -140,7 +160,7 @@ func jsonUnmarshalBool(buf []byte, _ Type, p *AttributePath) (Value, error) {
return Value{}, p.NewErrorf("unsupported type %T sent as %s", tok, Bool)
}

func jsonUnmarshalDynamicPseudoType(buf []byte, _ Type, p *AttributePath) (Value, error) {
func jsonUnmarshalDynamicPseudoType(buf []byte, _ Type, p *AttributePath, opts JSONOpts) (Value, error) {
dec := jsonByteDecoder(buf)
tok, err := dec.Token()
if err != nil {
Expand Down Expand Up @@ -190,10 +210,10 @@ func jsonUnmarshalDynamicPseudoType(buf []byte, _ Type, p *AttributePath) (Value
if valBody == nil {
return Value{}, p.NewErrorf("missing value in dynamically-typed value")
}
return jsonUnmarshal(valBody, t, p)
return jsonUnmarshal(valBody, t, p, opts)
}

func jsonUnmarshalList(buf []byte, elementType Type, p *AttributePath) (Value, error) {
func jsonUnmarshalList(buf []byte, elementType Type, p *AttributePath, opts JSONOpts) (Value, error) {
dec := jsonByteDecoder(buf)

tok, err := dec.Token()
Expand Down Expand Up @@ -227,7 +247,7 @@ func jsonUnmarshalList(buf []byte, elementType Type, p *AttributePath) (Value, e
if err != nil {
return Value{}, innerPath.NewErrorf("error decoding value: %w", err)
}
val, err := jsonUnmarshal(rawVal, elementType, innerPath)
val, err := jsonUnmarshal(rawVal, elementType, innerPath, opts)
if err != nil {
return Value{}, err
}
Expand All @@ -254,7 +274,7 @@ func jsonUnmarshalList(buf []byte, elementType Type, p *AttributePath) (Value, e
}, vals), nil
}

func jsonUnmarshalSet(buf []byte, elementType Type, p *AttributePath) (Value, error) {
func jsonUnmarshalSet(buf []byte, elementType Type, p *AttributePath, opts JSONOpts) (Value, error) {
dec := jsonByteDecoder(buf)

tok, err := dec.Token()
Expand Down Expand Up @@ -284,7 +304,7 @@ func jsonUnmarshalSet(buf []byte, elementType Type, p *AttributePath) (Value, er
if err != nil {
return Value{}, innerPath.NewErrorf("error decoding value: %w", err)
}
val, err := jsonUnmarshal(rawVal, elementType, innerPath)
val, err := jsonUnmarshal(rawVal, elementType, innerPath, opts)
if err != nil {
return Value{}, err
}
Expand All @@ -310,7 +330,7 @@ func jsonUnmarshalSet(buf []byte, elementType Type, p *AttributePath) (Value, er
}, vals), nil
}

func jsonUnmarshalMap(buf []byte, attrType Type, p *AttributePath) (Value, error) {
func jsonUnmarshalMap(buf []byte, attrType Type, p *AttributePath, opts JSONOpts) (Value, error) {
dec := jsonByteDecoder(buf)

tok, err := dec.Token()
Expand Down Expand Up @@ -341,7 +361,7 @@ func jsonUnmarshalMap(buf []byte, attrType Type, p *AttributePath) (Value, error
if err != nil {
return Value{}, innerPath.NewErrorf("error decoding value: %w", err)
}
val, err := jsonUnmarshal(rawVal, attrType, innerPath)
val, err := jsonUnmarshal(rawVal, attrType, innerPath, opts)
if err != nil {
return Value{}, err
}
Expand All @@ -360,7 +380,7 @@ func jsonUnmarshalMap(buf []byte, attrType Type, p *AttributePath) (Value, error
}, vals), nil
}

func jsonUnmarshalTuple(buf []byte, elementTypes []Type, p *AttributePath) (Value, error) {
func jsonUnmarshalTuple(buf []byte, elementTypes []Type, p *AttributePath, opts JSONOpts) (Value, error) {
dec := jsonByteDecoder(buf)

tok, err := dec.Token()
Expand Down Expand Up @@ -398,7 +418,7 @@ func jsonUnmarshalTuple(buf []byte, elementTypes []Type, p *AttributePath) (Valu
if err != nil {
return Value{}, innerPath.NewErrorf("error decoding value: %w", err)
}
val, err := jsonUnmarshal(rawVal, elementType, innerPath)
val, err := jsonUnmarshal(rawVal, elementType, innerPath, opts)
if err != nil {
return Value{}, err
}
Expand All @@ -422,7 +442,11 @@ func jsonUnmarshalTuple(buf []byte, elementTypes []Type, p *AttributePath) (Valu
}, vals), nil
}

func jsonUnmarshalObject(buf []byte, attrTypes map[string]Type, p *AttributePath) (Value, error) {
// jsonUnmarshalObject attempts to decode JSON object structure to tftypes.Value object.
// opts contains fields that can be used to modify the behaviour of JSON unmarshalling.
// ignoreUndefinedAttributes is used to ignore any attributes which appear in the JSON but do not have a corresponding
// entry in the schema. For example, raw state where an attribute has been removed from the schema.
func jsonUnmarshalObject(buf []byte, attrTypes map[string]Type, p *AttributePath, opts JSONOpts) (Value, error) {
dec := jsonByteDecoder(buf)

tok, err := dec.Token()
Expand All @@ -446,6 +470,12 @@ func jsonUnmarshalObject(buf []byte, attrTypes map[string]Type, p *AttributePath
}
attrType, ok := attrTypes[key]
if !ok {
if opts.IgnoreUndefinedAttributes {
// We are trying to ignore the key and value of any unsupported attribute.
_ = dec.Decode(new(json.RawMessage))
continue
}

return Value{}, innerPath.NewErrorf("unsupported attribute %q", key)
}
innerPath = p.WithAttributeName(key)
Expand All @@ -455,7 +485,7 @@ func jsonUnmarshalObject(buf []byte, attrTypes map[string]Type, p *AttributePath
if err != nil {
return Value{}, innerPath.NewErrorf("error decoding value: %w", err)
}
val, err := jsonUnmarshal(rawVal, attrType, innerPath)
val, err := jsonUnmarshal(rawVal, attrType, innerPath, opts)
if err != nil {
return Value{}, err
}
Expand Down
44 changes: 44 additions & 0 deletions tftypes/value_json_test.go
View file
Expand Up @@ -380,3 +380,47 @@ func TestValueFromJSON(t *testing.T) {
})
}
}

func TestValueFromJSONWithOpts(t *testing.T) {
t.Parallel()
type testCase struct {
value Value
typ Type
json string
}
tests := map[string]testCase{
"object-with-missing-attribute": {
value: NewValue(Object{
AttributeTypes: map[string]Type{
"bool": Bool,
"number": Number,
},
}, map[string]Value{
"bool": NewValue(Bool, true),
"number": NewValue(Number, big.NewFloat(0)),
}),
typ: Object{
AttributeTypes: map[string]Type{
"bool": Bool,
"number": Number,
},
},
json: `{"bool":true,"number":0,"unknown":"whatever"}`,
},
}
for name, test := range tests {
name, test := name, test
t.Run(name, func(t *testing.T) {
t.Parallel()
val, err := ValueFromJSONWithOpts([]byte(test.json), test.typ, JSONOpts{
IgnoreUndefinedAttributes: true,
})
if err != nil {
t.Fatalf("unexpected error unmarshaling: %s", err)
}
if diff := cmp.Diff(test.value, val); diff != "" {
t.Errorf("Unexpected results (-wanted +got): %s", diff)
}
})
}
}

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