engine: resources: Receive keys should match mcl, not golang

The capitalization of these keys was wrong and they weren't getting
seen. Add a test as well.

docs/resource-guide.md

@@ -678,10 +678,10 @@ receiving one. This can _only_ be done inside of the `CheckApply` function!
 
 ```golang
 // inside CheckApply, probably near the top
-if val, exists := obj.init.Recv()["SomeKey"]; exists {
-	obj.init.Logf("the SomeKey param was sent to us from: %s.%s", val.Res, val.Key)
+if val, exists := obj.init.Recv()["some_key"]; exists {
+	obj.init.Logf("the some_key param was sent to us from: %s.%s", val.Res, val.Key)
 	if val.Changed {
-		obj.init.Logf("the SomeKey param was just updated!")
+		obj.init.Logf("the some_key param was just updated!")
 		// you may want to invalidate some local cache
 	}
 }

engine/resources/file.go

@@ -1226,9 +1226,9 @@ func (obj *FileRes) CheckApply(ctx context.Context, apply bool) (bool, error) {
 	// might not have a new value to copy, and therefore we won't see this
 	// notification of change. Therefore, it is important to process these
 	// promptly, if they must not be lost, such as for cache invalidation.
-	if val, exists := obj.init.Recv()["Content"]; exists && val.Changed {
+	if val, exists := obj.init.Recv()["content"]; exists && val.Changed {
 		// if we received on Content, and it changed, invalidate the cache!
-		obj.init.Logf("contentCheckApply: invalidating sha256sum of `Content`")
+		obj.init.Logf("contentCheckApply: invalidating sha256sum of `content`")
 		obj.sha256sum = "" // invalidate!!
 	}
 

engine/resources/kv.go

@@ -282,9 +282,9 @@ func (obj *KVRes) CheckApply(ctx context.Context, apply bool) (bool, error) {
 		}
 	}()
 
-	if val, exists := obj.init.Recv()["Value"]; exists && val.Changed {
+	if val, exists := obj.init.Recv()["value"]; exists && val.Changed {
 		// if we received on Value, and it changed, wooo, nothing to do.
-		obj.init.Logf("CheckApply: `Value` was updated!")
+		obj.init.Logf("CheckApply: `value` was updated!")
 	}
 
 	value, exists, err := obj.kvGet(ctx, obj.getKey())

engine/resources/print.go

@@ -85,9 +85,9 @@ func (obj *PrintRes) Watch(ctx context.Context) error {
 // CheckApply method for Print resource. Does nothing, returns happy!
 func (obj *PrintRes) CheckApply(ctx context.Context, apply bool) (bool, error) {
 	obj.init.Logf("CheckApply: %t", apply)
-	if val, exists := obj.init.Recv()["Msg"]; exists && val.Changed {
+	if val, exists := obj.init.Recv()["msg"]; exists && val.Changed {
 		// if we received on Msg, and it changed, log message
-		obj.init.Logf("CheckApply: Received `Msg` of: %s", obj.Msg)
+		obj.init.Logf("CheckApply: Received `msg` of: %s", obj.Msg)
 	}
 
 	var refresh = obj.init.Refresh()

engine/resources/test.go

@@ -96,6 +96,7 @@ type TestRes struct {
 	AlwaysGroup   bool      `lang:"alwaysgroup" yaml:"always_group"`     // set to true to cause auto grouping
 	CompareFail   bool      `lang:"comparefail" yaml:"compare_fail"`     // will compare fail?
 	SendValue     string    `lang:"sendvalue" yaml:"send_value"`         // what value should we send?
+	ExpectRecv    *[]string `lang:"expectrecv" yaml:"expect_recv"`       // what keys should we expect from send/recv?
 	OnlyShow      []string  `lang:"onlyshow" yaml:"only_show"`           // what values do we show?
 
 	// TODO: add more fun properties!
@@ -146,14 +147,20 @@ func (obj *TestRes) Watch(ctx context.Context) error {
 
 // CheckApply method for Test resource. Does nothing, returns happy!
 func (obj *TestRes) CheckApply(ctx context.Context, apply bool) (bool, error) {
+	expectRecv := []string{}
 	for key, val := range obj.init.Recv() {
 		obj.init.Logf("CheckApply: Received `%s`, changed: %t", key, val.Changed)
+		expectRecv = append(expectRecv, key)
 	}
 
 	if obj.init.Refresh() {
 		obj.init.Logf("Received a notification!")
 	}
 
+	if obj.ExpectRecv != nil && len(*obj.ExpectRecv) != len(expectRecv) {
+		return false, fmt.Errorf("the received keys differ from expected, got: %+v", expectRecv)
+	}
+
 	fakeLogf := func(format string, v ...interface{}) {
 		key := format[0:strings.LastIndex(format, ":")]
 		if len(obj.OnlyShow) == 0 || util.StrInList(key, obj.OnlyShow) {
@@ -372,6 +379,19 @@ func (obj *TestRes) Cmp(r engine.Res) error {
 	if obj.SendValue != res.SendValue {
 		return fmt.Errorf("the SendValue differs")
 	}
+	if (obj.ExpectRecv == nil) != (res.ExpectRecv == nil) { // xor
+		return fmt.Errorf("the ExpectRecv differs")
+	}
+	if obj.ExpectRecv != nil && res.ExpectRecv != nil {
+		if len(*obj.ExpectRecv) != len(*res.ExpectRecv) {
+			return fmt.Errorf("the length of ExpectRecv differs")
+		}
+		for i, x := range *obj.ExpectRecv {
+			if x != (*res.ExpectRecv)[i] {
+				return fmt.Errorf("the item at ExpectRecv index %d differs", i)
+			}
+		}
+	}
 	if len(obj.OnlyShow) != len(res.OnlyShow) {
 		return fmt.Errorf("the length of OnlyShow differs")
 	}

engine/resources/test_test.go

@@ -168,6 +168,7 @@ func TestLowerStructFieldNameToFieldName2(t *testing.T) {
 		"alwaysgroup":   "AlwaysGroup",
 		"comparefail":   "CompareFail",
 		"sendvalue":     "SendValue",
+		"expectrecv":    "ExpectRecv",
 		"onlyshow":      "OnlyShow",
 
 		"comment": "Comment",

engine/resources/value.go

@@ -126,9 +126,9 @@ func (obj *ValueRes) CheckApply(ctx context.Context, apply bool) (bool, error) {
 	received := false
 	different := false
 	checkOK := false
-	if val, exists := obj.init.Recv()["Any"]; exists && val.Changed {
+	if val, exists := obj.init.Recv()["any"]; exists && val.Changed {
 		// if we received on Any, and it changed, invalidate the cache!
-		obj.init.Logf("CheckApply: received on `Any`")
+		obj.init.Logf("CheckApply: received on `any`")
 		obj.isSet = true // we received something
 		obj.cachedAny = obj.Any
 		received = true // we'll always need to send below when we recv

lang/interpret_test/TestAstFunc3/sendrecv-simple0.txtar

@@ -0,0 +1,27 @@
+-- main.mcl --
+# send/recv of value1.any into test.msg works!
+value "value1" {
+	any => "i am value1",
+}
+test "test1" {
+	sendvalue => "hello from test",
+	expectrecv => ["anotherstr",],	# expecting to recv on these keys!
+
+	Meta:autogroup => false,
+}
+print "print1" {
+	#msg => "",	# gets value from send_value above
+}
+Value["value1"].any -> Test["test1"].anotherstr
+Test["test1"].hello -> Print["print1"].msg
+-- OUTPUT --
+Edge: test[test1] -> print[print1] # test[test1] -> print[print1]
+Edge: value[value1] -> test[test1] # value[value1] -> test[test1]
+Field: print[print1].Msg = "hello from test"
+Field: test[test1].AnotherStr = "i am value1"
+Field: test[test1].ExpectRecv = ["anotherstr"]
+Field: test[test1].SendValue = "hello from test"
+Field: value[value1].Any = "i am value1"
+Vertex: print[print1]
+Vertex: test[test1]
+Vertex: value[value1]