add async parser tests for leading dots (and make changes to get them to pass) (#799)

Author: pjfanning

src/main/java/com/fasterxml/jackson/core/json/async/NonBlockingJsonParser.java

@@ -1574,6 +1574,17 @@ protected JsonToken _finishNumberPlusMinus(final int ch, final boolean negative)
                     }
                     return _finishNumberLeadingPosZeroes();
                 }
+            } else if (ch == INT_PERIOD && isEnabled(JsonReadFeature.ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS.mappedFeature())) {
+                if (negative) {
+                    _inputPtr--;
+                    return _finishNumberLeadingNegZeroes();
+                } else {
+                    if (!isEnabled(JsonReadFeature.ALLOW_LEADING_PLUS_SIGN_FOR_NUMBERS.mappedFeature())) {
+                        _reportUnexpectedNumberChar('+', "JSON spec does not allow numbers to have plus signs: enable `JsonReadFeature.ALLOW_LEADING_PLUS_SIGN_FOR_NUMBERS` to allow");
+                    }
+                    _inputPtr--;
+                    return _finishNumberLeadingPosZeroes();
+                }
             }
             final String message = negative ?
                 "expected digit (0-9) to follow minus sign, for valid numeric value" :

src/test/java/com/fasterxml/jackson/core/json/async/AsyncNonStandardNumberParsingTest.java

@@ -220,6 +220,76 @@ public void testLeadingPlusSignInDecimalEnabled2() throws Exception {
         }
     }
 
+    public void testLeadingPlusSignInDecimalEnabled3() throws Exception {
+        final String JSON = "[ +123.123 ]";
+
+        JsonFactory jsonFactory =
+                JsonFactory.builder().enable(JsonReadFeature.ALLOW_LEADING_PLUS_SIGN_FOR_NUMBERS).build();
+        AsyncReaderWrapper p = createParser(jsonFactory, JSON, 1);
+        assertToken(JsonToken.START_ARRAY, p.nextToken());
+        try {
+            assertEquals(JsonToken.VALUE_NUMBER_FLOAT, p.nextToken());
+            assertEquals(123.123, p.getDoubleValue());
+            assertEquals("123.123", p.getDecimalValue().toString());
+            assertEquals("+123.123", p.currentText());
+        } finally {
+            p.close();
+        }
+    }
+
+    public void testLeadingPlusSignNoLeadingZeroDisabled() throws Exception {
+        final String JSON = "[ +.123 ]";
+
+        JsonFactory jsonFactory = JsonFactory.builder()
+                .enable(JsonReadFeature.ALLOW_LEADING_PLUS_SIGN_FOR_NUMBERS)
+                .build();
+        AsyncReaderWrapper p = createParser(jsonFactory, JSON, 1);
+        assertToken(JsonToken.START_ARRAY, p.nextToken());
+        try {
+            p.nextToken();
+            fail("Expected exception");
+        } catch (StreamReadException e) {
+            verifyException(e, "Unexpected character ('.'");
+        }
+    }
+
+    public void testLeadingPlusSignNoLeadingZeroEnabled() throws Exception {
+        final String JSON = "[ +.123 ]";
+
+        JsonFactory jsonFactory = JsonFactory.builder()
+                .enable(JsonReadFeature.ALLOW_LEADING_PLUS_SIGN_FOR_NUMBERS)
+                .enable(JsonReadFeature.ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS)
+                .build();
+        AsyncReaderWrapper p = createParser(jsonFactory, JSON, 1);
+        assertToken(JsonToken.START_ARRAY, p.nextToken());
+        try {
+            assertEquals(JsonToken.VALUE_NUMBER_FLOAT, p.nextToken());
+            assertEquals(0.123, p.getDoubleValue());
+            assertEquals("0.123", p.getDecimalValue().toString());
+            assertEquals("+0.123", p.currentText());
+        } finally {
+            p.close();
+        }
+    }
+
+    public void testLeadingDotInNegativeDecimalEnabled() throws Exception {
+        final String JSON = "[ -.123 ]";
+        final JsonFactory factory = JsonFactory.builder()
+                .enable(JsonReadFeature.ALLOW_LEADING_DECIMAL_POINT_FOR_NUMBERS)
+                .build();
+
+        AsyncReaderWrapper p = createParser(factory, JSON, 1);
+        assertToken(JsonToken.START_ARRAY, p.nextToken());
+        try {
+            assertEquals(JsonToken.VALUE_NUMBER_FLOAT, p.nextToken());
+            assertEquals(-0.123, p.getDoubleValue());
+            assertEquals("-0.123", p.getDecimalValue().toString());
+            assertEquals("-0.123", p.currentText());
+        } finally {
+            p.close();
+        }
+    }
+
     /**
      * The format "NNN." (as opposed to "NNN") is not valid JSON, so this should fail
      */