Detect IncompleteInput in false, true, and null

CHANGELOG.md

@@ -15,6 +15,7 @@ HEAD
 * Renamed `JsonObject::getOrCreate()` to `getOrAddMember()`
 * Fixed `JsonVariant::isNull()` not returning `true` after `set((char*)0)`
 * Fixed segfault after `variant.set(serialized((char*)0))`
+* Detect `IncompleteInput` in `false`, `true`, and `null`
 
 v6.8.0-beta (2019-01-30)
 -----------

src/ArduinoJson/Json/JsonDeserializer.hpp

@@ -253,19 +253,30 @@ class JsonDeserializer {
 
     if (isInteger(buffer)) {
       result.setInteger(parseInteger<Integer>(buffer));
-    } else if (isFloat(buffer)) {
-      result.setFloat(parseFloat<Float>(buffer));
-    } else if (!strcmp(buffer, "true")) {
-      result.setBoolean(true);
-    } else if (!strcmp(buffer, "false")) {
-      result.setBoolean(false);
-    } else if (!strcmp(buffer, "null")) {
-      // already null
-    } else {
-      return DeserializationError::InvalidInput;
-    }
       return DeserializationError::Ok;
     }
+    if (isFloat(buffer)) {
+      result.setFloat(parseFloat<Float>(buffer));
+      return DeserializationError::Ok;
+    }
+    c = buffer[0];
+    if (c == 't') {  // true
+      result.setBoolean(true);
+      return n == 4 ? DeserializationError::Ok
+                    : DeserializationError::IncompleteInput;
+    }
+    if (c == 'f') {  // false
+      result.setBoolean(false);
+      return n == 5 ? DeserializationError::Ok
+                    : DeserializationError::IncompleteInput;
+    }
+    if (c == 'n') {  // null
+      // the variant is already null
+      return n == 4 ? DeserializationError::Ok
+                    : DeserializationError::IncompleteInput;
+    }
+    return DeserializationError::InvalidInput;
+  }
 
   DeserializationError parseCodepoint(uint16_t &codepoint) {
     codepoint = 0;

test/JsonDeserializer/CMakeLists.txt

@@ -11,6 +11,8 @@ add_executable(JsonDeserializerTests
 	deserializeJsonValue.cpp
 	deserializeJsonString.cpp
 	input_types.cpp
+	incomplete_input.cpp
+	invalid_input.cpp
 	nestingLimit.cpp
 )
 

test/JsonDeserializer/deserializeJsonString.cpp

@@ -6,8 +6,6 @@
 #include <ArduinoJson.h>
 #include <catch.hpp>
 
-using namespace Catch::Matchers;
-
 TEST_CASE("Valid JSON strings value") {
   struct TestCase {
     const char* input;

test/JsonDeserializer/incomplete_input.cpp

@@ -0,0 +1,27 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#define ARDUINOJSON_DECODE_UNICODE 1
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("Truncated JSON input") {
+  const char* testCases[] = {"\"hello", "\'hello", "'\\u", "'\\u00", "'\\u000",
+                             // false
+                             "f", "fa", "fal", "fals",
+                             // true
+                             "t", "tr", "tru",
+                             // null
+                             "n", "nu", "nul"};
+  const size_t testCount = sizeof(testCases) / sizeof(testCases[0]);
+
+  DynamicJsonDocument doc(4096);
+
+  for (size_t i = 0; i < testCount; i++) {
+    const char* input = testCases[i];
+    CAPTURE(input);
+    REQUIRE(deserializeJson(doc, input) ==
+            DeserializationError::IncompleteInput);
+  }
+}

test/JsonDeserializer/invalid_input.cpp

@@ -0,0 +1,34 @@
+// ArduinoJson - arduinojson.org
+// Copyright Benoit Blanchon 2014-2019
+// MIT License
+
+#define ARDUINOJSON_DECODE_UNICODE 1
+#include <ArduinoJson.h>
+#include <catch.hpp>
+
+TEST_CASE("Invalid JSON input") {
+  const char* testCases[] = {"'\\u'",     "'\\u000g'", "'\\u000'",
+                             "'\\u000G'", "'\\u000/'", "\\x1234"};
+  const size_t testCount = sizeof(testCases) / sizeof(testCases[0]);
+
+  DynamicJsonDocument doc(4096);
+
+  for (size_t i = 0; i < testCount; i++) {
+    const char* input = testCases[i];
+    CAPTURE(input);
+    REQUIRE(deserializeJson(doc, input) == DeserializationError::InvalidInput);
+  }
+}
+
+TEST_CASE("Invalid JSON input that should pass") {
+  const char* testCases[] = {"nulL", "tru3", "fals3"};
+  const size_t testCount = sizeof(testCases) / sizeof(testCases[0]);
+
+  DynamicJsonDocument doc(4096);
+
+  for (size_t i = 0; i < testCount; i++) {
+    const char* input = testCases[i];
+    CAPTURE(input);
+    REQUIRE(deserializeJson(doc, input) == DeserializationError::Ok);
+  }
+}