[pubsub/query] quote values using single quotes

This fixes the problem with base-16 encoded values which may start with
digits: 015AB.... In such cases, the parser recognizes them as numbers
but fails to parse because of the follow-up characters (AB).

```
failed to parse tm.events.type=Tx AND hash=136E18F7E4C348B780CF873A0BF43922E5BAFA63:
parse error near digit (line 1 symbol 31 - line 1 symbol 32):
  "6"
```

So, from now on we should quote any values. This seems to be the way
Postgresql has chosen.

pubsub/example_test.go

@@ -19,7 +19,7 @@ func TestExample(t *testing.T) {
 
 	ctx := context.Background()
 	ch := make(chan interface{}, 1)
-	err := s.Subscribe(ctx, "example-client", query.MustParse("abci.account.name=John"), ch)
+	err := s.Subscribe(ctx, "example-client", query.MustParse("abci.account.name='John'"), ch)
 	require.NoError(t, err)
 	err = s.PublishWithTags(ctx, "Tombstone", map[string]interface{}{"abci.account.name": "John"})
 	require.NoError(t, err)

pubsub/pubsub_test.go

@@ -46,14 +46,14 @@ func TestDifferentClients(t *testing.T) {
 
 	ctx := context.Background()
 	ch1 := make(chan interface{}, 1)
-	err := s.Subscribe(ctx, "client-1", query.MustParse("tm.events.type=NewBlock"), ch1)
+	err := s.Subscribe(ctx, "client-1", query.MustParse("tm.events.type='NewBlock'"), ch1)
 	require.NoError(t, err)
 	err = s.PublishWithTags(ctx, "Iceman", map[string]interface{}{"tm.events.type": "NewBlock"})
 	require.NoError(t, err)
 	assertReceive(t, "Iceman", ch1)
 
 	ch2 := make(chan interface{}, 1)
-	err = s.Subscribe(ctx, "client-2", query.MustParse("tm.events.type=NewBlock AND abci.account.name=Igor"), ch2)
+	err = s.Subscribe(ctx, "client-2", query.MustParse("tm.events.type='NewBlock' AND abci.account.name='Igor'"), ch2)
 	require.NoError(t, err)
 	err = s.PublishWithTags(ctx, "Ultimo", map[string]interface{}{"tm.events.type": "NewBlock", "abci.account.name": "Igor"})
 	require.NoError(t, err)
@@ -61,7 +61,7 @@ func TestDifferentClients(t *testing.T) {
 	assertReceive(t, "Ultimo", ch2)
 
 	ch3 := make(chan interface{}, 1)
-	err = s.Subscribe(ctx, "client-3", query.MustParse("tm.events.type=NewRoundStep AND abci.account.name=Igor AND abci.invoice.number = 10"), ch3)
+	err = s.Subscribe(ctx, "client-3", query.MustParse("tm.events.type='NewRoundStep' AND abci.account.name='Igor' AND abci.invoice.number = 10"), ch3)
 	require.NoError(t, err)
 	err = s.PublishWithTags(ctx, "Valeria Richards", map[string]interface{}{"tm.events.type": "NewRoundStep"})
 	require.NoError(t, err)
@@ -75,7 +75,7 @@ func TestClientSubscribesTwice(t *testing.T) {
 	defer s.Stop()
 
 	ctx := context.Background()
-	q := query.MustParse("tm.events.type=NewBlock")
+	q := query.MustParse("tm.events.type='NewBlock'")
 
 	ch1 := make(chan interface{}, 1)
 	err := s.Subscribe(ctx, clientID, q, ch1)
@@ -184,7 +184,7 @@ func benchmarkNClients(n int, b *testing.B) {
 			for range ch {
 			}
 		}()
-		s.Subscribe(ctx, clientID, query.MustParse(fmt.Sprintf("abci.Account.Owner = Ivan AND abci.Invoices.Number = %d", i)), ch)
+		s.Subscribe(ctx, clientID, query.MustParse(fmt.Sprintf("abci.Account.Owner = 'Ivan' AND abci.Invoices.Number = %d", i)), ch)
 	}
 
 	b.ReportAllocs()
@@ -200,7 +200,7 @@ func benchmarkNClientsOneQuery(n int, b *testing.B) {
 	defer s.Stop()
 
 	ctx := context.Background()
-	q := query.MustParse("abci.Account.Owner = Ivan AND abci.Invoices.Number = 1")
+	q := query.MustParse("abci.Account.Owner = 'Ivan' AND abci.Invoices.Number = 1")
 	for i := 0; i < n; i++ {
 		ch := make(chan interface{})
 		go func() {

pubsub/query/parser_test.go

@@ -13,30 +13,37 @@ func TestParser(t *testing.T) {
 		query string
 		valid bool
 	}{
-		{"tm.events.type=NewBlock", true},
-		{"tm.events.type = NewBlock", true},
-		{"tm.events.type=TIME", true},
-		{"tm.events.type=DATE", true},
+		{"tm.events.type='NewBlock'", true},
+		{"tm.events.type = 'NewBlock'", true},
+		{"tm.events.name = ''", true},
+		{"tm.events.type='TIME'", true},
+		{"tm.events.type='DATE'", true},
+		{"tm.events.type='='", true},
+		{"tm.events.type='TIME", false},
+		{"tm.events.type=TIME'", false},
 		{"tm.events.type==", false},
+		{"tm.events.type=NewBlock", false},
 		{">==", false},
-		{"tm.events.type NewBlock =", false},
-		{"tm.events.type>NewBlock", false},
+		{"tm.events.type 'NewBlock' =", false},
+		{"tm.events.type>'NewBlock'", false},
 		{"", false},
 		{"=", false},
-		{"=NewBlock", false},
+		{"='NewBlock'", false},
 		{"tm.events.type=", false},
 
 		{"tm.events.typeNewBlock", false},
+		{"tm.events.type'NewBlock'", false},
+		{"'NewBlock'", false},
 		{"NewBlock", false},
 		{"", false},
 
-		{"tm.events.type=NewBlock AND abci.account.name=Igor", true},
-		{"tm.events.type=NewBlock AND", false},
-		{"tm.events.type=NewBlock AN", false},
-		{"tm.events.type=NewBlock AN tm.events.type=NewBlockHeader", false},
-		{"AND tm.events.type=NewBlock ", false},
+		{"tm.events.type='NewBlock' AND abci.account.name='Igor'", true},
+		{"tm.events.type='NewBlock' AND", false},
+		{"tm.events.type='NewBlock' AN", false},
+		{"tm.events.type='NewBlock' AN tm.events.type='NewBlockHeader'", false},
+		{"AND tm.events.type='NewBlock' ", false},
 
-		{"abci.account.name CONTAINS Igor", true},
+		{"abci.account.name CONTAINS 'Igor'", true},
 
 		{"tx.date > DATE 2013-05-03", true},
 		{"tx.date < DATE 2013-05-03", true},

pubsub/query/query.go

@@ -94,9 +94,12 @@ func (q *Query) Matches(tags map[string]interface{}) bool {
 		case rulecontains:
 			op = opContains
 		case rulevalue:
+			// strip single quotes from value (i.e. "'NewBlock'" -> "NewBlock")
+			valueWithoutSingleQuotes := buffer[begin+1 : end-1]
+
 			// see if the triplet (tag, operator, operand) matches any tag
 			// "tx.gas", "=", "7", { "tx.gas": 7, "tx.ID": "4AE393495334" }
-			if !match(tag, op, reflect.ValueOf(buffer[begin:end]), tags) {
+			if !match(tag, op, reflect.ValueOf(valueWithoutSingleQuotes), tags) {
 				return false
 			}
 		case rulenumber:

pubsub/query/query.peg

@@ -13,8 +13,8 @@ condition <- tag ' '* (le ' '* (number / time / date)
                       / contains ' '* value
                       )
 
-tag <- < (![ \t\n\r\\()"=><] .)+ >
-value <- < (![ \t\n\r\\()"=><] .)+ >
+tag <- < (![ \t\n\r\\()"'=><] .)+ >
+value <- < '\'' (!["'] .)* '\''>
 number <- < ('0'
            / [1-9] digit* ('.' digit*)?) >
 digit <- [0-9]

pubsub/query/query_test.go

@@ -22,7 +22,7 @@ func TestMatches(t *testing.T) {
 		err     bool
 		matches bool
 	}{
-		{"tm.events.type=NewBlock", map[string]interface{}{"tm.events.type": "NewBlock"}, false, true},
+		{"tm.events.type='NewBlock'", map[string]interface{}{"tm.events.type": "NewBlock"}, false, true},
 
 		{"tx.gas > 7", map[string]interface{}{"tx.gas": 8}, false, true},
 		{"tx.gas > 7 AND tx.gas < 9", map[string]interface{}{"tx.gas": 8}, false, true},
@@ -40,8 +40,8 @@ func TestMatches(t *testing.T) {
 		{"tx.time >= TIME 2013-05-03T14:45:00Z", map[string]interface{}{"tx.time": time.Now()}, false, true},
 		{"tx.time = TIME 2013-05-03T14:45:00Z", map[string]interface{}{"tx.time": txTime}, false, false},
 
-		{"abci.owner.name CONTAINS Igor", map[string]interface{}{"abci.owner.name": "Igor,Ivan"}, false, true},
-		{"abci.owner.name CONTAINS Igor", map[string]interface{}{"abci.owner.name": "Pavel,Ivan"}, false, false},
+		{"abci.owner.name CONTAINS 'Igor'", map[string]interface{}{"abci.owner.name": "Igor,Ivan"}, false, true},
+		{"abci.owner.name CONTAINS 'Igor'", map[string]interface{}{"abci.owner.name": "Pavel,Ivan"}, false, false},
 	}
 
 	for _, tc := range testCases {
@@ -60,5 +60,5 @@ func TestMatches(t *testing.T) {
 
 func TestMustParse(t *testing.T) {
 	assert.Panics(t, func() { query.MustParse("=") })
-	assert.NotPanics(t, func() { query.MustParse("tm.events.type=NewBlock") })
+	assert.NotPanics(t, func() { query.MustParse("tm.events.type='NewBlock'") })
 }