[build] add facilities for using american fuzzy loopupstream/fuzzing

66 files changed, 594 insertions, 271 deletions

diff --git a/.gitignore b/.gitignore
index 16fd245107..275c296a26 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,7 @@ xcuserdata
 /test/fixtures/**/actual.png
 /test/fixtures/**/diff.png
 /test/output
+/test/fuzz-result
 /node_modules
 /platform/ios/benchmark/assets/glyphs/DIN*
 /platform/ios/benchmark/assets/tiles/mapbox.mapbox-terrain-v2,mapbox.mapbox-streets-v6
diff --git a/.mason b/.mason
-Subproject 39ed569b3a3dc1197bc00d423c63800c25dc17f
+Subproject c40d5468f8c7e0b037e0c46b78c2b88642d3e31
diff --git a/Makefile b/Makefile
index 4b10a77233..2a980336e8 100644
--- a/Makefile
+++ b/Makefile
@@ -363,6 +363,16 @@ check-linux: clang-tools-linux
 check-macos: clang-tools-macos
 	scripts/clang-tools.sh $(MACOS_OUTPUT_PATH)/$(BUILDTYPE) --diff
 
+fuzz-%: platform/macos/platform.gyp $(MACOS_OUTPUT_PATH)/config.gypi
+	.mason/mason install afl 2.19b
+	.mason/mason install clang 3.8.0
+	CXX=afl-clang-fast++ CC=afl-clang-fast $(GYP) -f ninja -I $(MACOS_OUTPUT_PATH)/config.gypi \
+	  --generator-output=$(MACOS_OUTPUT_PATH)/fuzz $<
+	PATH="`.mason/mason prefix afl 2.19b`/bin:`.mason/mason prefix clang 3.8.0`/bin:${PATH}" \
+		AFL_PATH=`.mason/mason prefix afl 2.19b`/lib/afl deps/ninja/ninja-macos -C $(MACOS_OUTPUT_PATH)/fuzz/$(BUILDTYPE) fuzz
+	scripts/fuzz.sh $(MACOS_OUTPUT_PATH)/fuzz/$(BUILDTYPE) $*
+
+
 #### Miscellaneous targets #####################################################
 
 style-code:
diff --git a/platform/linux/platform.gyp b/platform/linux/platform.gyp
index 7adf5337c4..5d3ab8b592 100644
--- a/platform/linux/platform.gyp
+++ b/platform/linux/platform.gyp
@@ -35,6 +35,25 @@
       ],
     },
     {
+      'target_name': 'fuzz',
+      'type': 'executable',
+
+      'dependencies': [
+        'test-lib',
+        'platform-lib',
+        'copy_certificate_bundle',
+      ],
+
+      'include_dirs': [
+        '../../include',
+        '../../src',
+      ],
+
+      'sources': [
+        '../../test/src/fuzz.cpp',
+      ],
+    },
+    {
       'target_name': 'benchmark',
       'type': 'executable',
 
diff --git a/platform/macos/platform.gyp b/platform/macos/platform.gyp
index 68ab4ce467..9d64c956cf 100644
--- a/platform/macos/platform.gyp
+++ b/platform/macos/platform.gyp
@@ -27,6 +27,42 @@
         '../../test/src/main.cpp',
       ],
     },
+      {
+      'target_name': 'fuzz',
+      'type': 'executable',
+
+      'dependencies': [
+        'platform-lib',
+      ],
+
+      'include_dirs': [
+        '../../include',
+        '../../src',
+      ],
+
+      'sources': [
+        '../../test/src/fuzz.cpp',
+      ],
+
+      'variables': {
+        'cflags_cc': [
+          '<@(rapidjson_cflags)',
+          '<@(variant_cflags)',
+          '<@(geometry_cflags)',
+          '<@(protozero_cflags)',
+        ],
+      },
+
+      'conditions': [
+        ['OS == "mac"', {
+          'xcode_settings': {
+            'OTHER_CPLUSPLUSFLAGS': [ '<@(cflags_cc)' ],
+          },
+        }, {
+         'cflags_cc': [ '<@(cflags_cc)' ],
+        }],
+      ],
+    },
     {
       'target_name': 'benchmark',
       'type': 'executable',
diff --git a/scripts/export-xcconfig.py b/scripts/export-xcconfig.py
index 75fe933e24..ae9fa9c6bb 100755
--- a/scripts/export-xcconfig.py
+++ b/scripts/export-xcconfig.py
@@ -1,13 +1,18 @@
 #!/usr/bin/env python
 
-import sys, ast, re
+import sys, ast, re, os
 
 ILLEGAL_CHAR_RE = re.compile(r"\W")
 
+env_vars = ['CC', 'CXX']
+
 def main():
     with open(sys.argv[1], "r") as in_file, open(sys.argv[2], "w") as out_file:
         config = ast.literal_eval(in_file.read())
         variables = ["// Do not edit -- generated by export-xcconfig.py\n"]
+        for var in env_vars:
+            if os.environ.get(var):
+                variables.append("%s = %s\n" % (var, os.environ.get(var)))
         assert(type(config) is dict)
         assert(type(config["variables"]) is dict)
         for variable, flags in config["variables"].iteritems():
diff --git a/scripts/fuzz.sh b/scripts/fuzz.sh
new file mode 100755
index 0000000000..047e55cad7
--- /dev/null
+++ b/scripts/fuzz.sh
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+set -e
+set -o pipefail
+
+export PATH="`pwd`/.mason:${PATH}" MASON_DIR="`pwd`/.mason"
+
+AFL_PREFIX=$(mason prefix afl 2.19b)
+AFL_FUZZ=${AFL_PREFIX}/bin/afl-fuzz
+
+
+if [ -z "$2" ]; then
+    echo "Usage: $0 <build path> <name>"
+    exit 1
+fi
+
+if [ ! -d "test/fuzz-input/$2" ]; then
+    echo "Fuzzing data for '$2' does not exist."
+    exit 1
+fi
+
+FUZZ=$1/fuzz
+${FUZZ} $2 < /dev/null
+
+rm -rf test/fuzz-result/$2
+mkdir -p test/fuzz-result/$2
+
+${AFL_FUZZ} -i test/fuzz-input/$2 -o test/fuzz-result/$2 ${FUZZ} $2
diff --git a/src/mbgl/tile/vector_tile.cpp b/src/mbgl/tile/vector_tile.cpp
index 6a3c51c05d..784b6cb1ab 100644
--- a/src/mbgl/tile/vector_tile.cpp
+++ b/src/mbgl/tile/vector_tile.cpp
@@ -1,10 +1,8 @@
 #include <mbgl/tile/vector_tile.hpp>
+#include <mbgl/tile/vector_tile_data.hpp>
 #include <mbgl/tile/tile_loader_impl.hpp>
-#include <mbgl/tile/geometry_tile_data.hpp>
 #include <mbgl/style/update_parameters.hpp>
 
-#include <protozero/pbf_reader.hpp>
-
 #include <map>
 #include <unordered_map>
 #include <functional>
@@ -12,62 +10,6 @@
 
 namespace mbgl {
 
-class VectorTileLayer;
-
-using pbf_iter_type = protozero::pbf_reader::const_uint32_iterator;
-using packed_iter_type = std::pair<pbf_iter_type,pbf_iter_type>;
-
-class VectorTileFeature : public GeometryTileFeature {
-public:
-    VectorTileFeature(protozero::pbf_reader, const VectorTileLayer&);
-
-    FeatureType getType() const override { return type; }
-    optional<Value> getValue(const std::string&) const override;
-    std::unordered_map<std::string,Value> getProperties() const override;
-    optional<FeatureIdentifier> getID() const override;
-    GeometryCollection getGeometries() const override;
-
-private:
-    const VectorTileLayer& layer;
-    optional<FeatureIdentifier> id;
-    FeatureType type = FeatureType::Unknown;
-    packed_iter_type tags_iter;
-    packed_iter_type geometry_iter;
-};
-
-class VectorTileLayer : public GeometryTileLayer {
-public:
-    VectorTileLayer(protozero::pbf_reader);
-
-    std::size_t featureCount() const override { return features.size(); }
-    util::ptr<const GeometryTileFeature> getFeature(std::size_t) const override;
-    std::string getName() const override;
-
-private:
-    friend class VectorTileData;
-    friend class VectorTileFeature;
-
-    std::string name;
-    uint32_t version = 1;
-    uint32_t extent = 4096;
-    std::map<std::string, uint32_t> keysMap;
-    std::vector<std::reference_wrapper<const std::string>> keys;
-    std::vector<Value> values;
-    std::vector<protozero::pbf_reader> features;
-};
-
-class VectorTileData : public GeometryTileData {
-public:
-    VectorTileData(std::shared_ptr<const std::string> data);
-
-    util::ptr<GeometryTileLayer> getLayer(const std::string&) const override;
-
-private:
-    std::shared_ptr<const std::string> data;
-    mutable bool parsed = false;
-    mutable std::map<std::string, util::ptr<GeometryTileLayer>> layers;
-};
-
 VectorTile::VectorTile(const OverscaledTileID& id_,
                        std::string sourceID_,
                        const style::UpdateParameters& parameters,
@@ -89,215 +31,4 @@ void VectorTile::setData(std::shared_ptr<const std::string> data_,
     GeometryTile::setData(data_ ? std::make_unique<VectorTileData>(data_) : nullptr);
 }
 
-Value parseValue(protozero::pbf_reader data) {
-    while (data.next())
-    {
-        switch (data.tag()) {
-        case 1: // string_value
-            return data.get_string();
-        case 2: // float_value
-            return static_cast<double>(data.get_float());
-        case 3: // double_value
-            return data.get_double();
-        case 4: // int_value
-            return data.get_int64();
-        case 5: // uint_value
-            return data.get_uint64();
-        case 6: // sint_value
-            return data.get_sint64();
-        case 7: // bool_value
-            return data.get_bool();
-        default:
-            data.skip();
-            break;
-        }
-    }
-    return false;
-}
-
-VectorTileFeature::VectorTileFeature(protozero::pbf_reader feature_pbf, const VectorTileLayer& layer_)
-    : layer(layer_) {
-    while (feature_pbf.next()) {
-        switch (feature_pbf.tag()) {
-        case 1: // id
-            id = { feature_pbf.get_uint64() };
-            break;
-        case 2: // tags
-            tags_iter = feature_pbf.get_packed_uint32();
-            break;
-        case 3: // type
-            type = static_cast<FeatureType>(feature_pbf.get_enum());
-            break;
-        case 4: // geometry
-            geometry_iter = feature_pbf.get_packed_uint32();
-            break;
-        default:
-            feature_pbf.skip();
-            break;
-        }
-    }
-}
-
-optional<Value> VectorTileFeature::getValue(const std::string& key) const {
-    auto keyIter = layer.keysMap.find(key);
-    if (keyIter == layer.keysMap.end()) {
-        return optional<Value>();
-    }
-
-    auto start_itr = tags_iter.first;
-    const auto & end_itr = tags_iter.second;
-    while (start_itr != end_itr) {
-        uint32_t tag_key = static_cast<uint32_t>(*start_itr++);
-
-        if (layer.keysMap.size() <= tag_key) {
-            throw std::runtime_error("feature referenced out of range key");
-        }
-
-        if (start_itr == end_itr) {
-            throw std::runtime_error("uneven number of feature tag ids");
-        }
-
-        uint32_t tag_val = static_cast<uint32_t>(*start_itr++);;
-        if (layer.values.size() <= tag_val) {
-            throw std::runtime_error("feature referenced out of range value");
-        }
-
-        if (tag_key == keyIter->second) {
-            return layer.values[tag_val];
-        }
-    }
-
-    return optional<Value>();
-}
-
-std::unordered_map<std::string,Value> VectorTileFeature::getProperties() const {
-    std::unordered_map<std::string,Value> properties;
-    auto start_itr = tags_iter.first;
-    const auto & end_itr = tags_iter.second;
-    while (start_itr != end_itr) {
-        uint32_t tag_key = static_cast<uint32_t>(*start_itr++);
-        if (start_itr == end_itr) {
-            throw std::runtime_error("uneven number of feature tag ids");
-        }
-        uint32_t tag_val = static_cast<uint32_t>(*start_itr++);
-        properties[layer.keys.at(tag_key)] = layer.values.at(tag_val);
-    }
-    return properties;
-}
-
-optional<FeatureIdentifier> VectorTileFeature::getID() const {
-    return id;
-}
-
-GeometryCollection VectorTileFeature::getGeometries() const {
-    uint8_t cmd = 1;
-    uint32_t length = 0;
-    int32_t x = 0;
-    int32_t y = 0;
-    const float scale = float(util::EXTENT) / layer.extent;
-
-    GeometryCollection lines;
-
-    lines.emplace_back();
-    GeometryCoordinates* line = &lines.back();
-
-    auto g_itr = geometry_iter;
-    while (g_itr.first != g_itr.second) {
-        if (length == 0) {
-            uint32_t cmd_length = static_cast<uint32_t>(*g_itr.first++);
-            cmd = cmd_length & 0x7;
-            length = cmd_length >> 3;
-        }
-
-        --length;
-
-        if (cmd == 1 || cmd == 2) {
-            x += protozero::decode_zigzag32(static_cast<uint32_t>(*g_itr.first++));
-            y += protozero::decode_zigzag32(static_cast<uint32_t>(*g_itr.first++));
-
-            if (cmd == 1 && !line->empty()) { // moveTo
-                lines.emplace_back();
-                line = &lines.back();
-            }
-
-            line->emplace_back(::round(x * scale), ::round(y * scale));
-
-        } else if (cmd == 7) { // closePolygon
-            if (!line->empty()) {
-                line->push_back((*line)[0]);
-            }
-
-        } else {
-            throw std::runtime_error("unknown command");
-        }
-    }
-
-    if (layer.version >= 2 || type != FeatureType::Polygon) {
-        return lines;
-    }
-
-    return fixupPolygons(lines);
-}
-
-VectorTileData::VectorTileData(std::shared_ptr<const std::string> data_)
-    : data(std::move(data_)) {
-}
-
-util::ptr<GeometryTileLayer> VectorTileData::getLayer(const std::string& name) const {
-    if (!parsed) {
-        parsed = true;
-        protozero::pbf_reader tile_pbf(*data);
-        while (tile_pbf.next(3)) {
-            util::ptr<VectorTileLayer> layer = std::make_shared<VectorTileLayer>(tile_pbf.get_message());
-            layers.emplace(layer->name, layer);
-        }
-    }
-
-    auto layer_it = layers.find(name);
-    if (layer_it != layers.end()) {
-        return layer_it->second;
-    }
-
-    return nullptr;
-}
-
-VectorTileLayer::VectorTileLayer(protozero::pbf_reader layer_pbf) {
-    while (layer_pbf.next()) {
-        switch (layer_pbf.tag()) {
-        case 1: // name
-            name = layer_pbf.get_string();
-            break;
-        case 2: // feature
-            features.push_back(layer_pbf.get_message());
-            break;
-        case 3: // keys
-            {
-                auto iter = keysMap.emplace(layer_pbf.get_string(), keysMap.size());
-                keys.emplace_back(std::reference_wrapper<const std::string>(iter.first->first));
-            }
-            break;
-        case 4: // values
-            values.emplace_back(parseValue(layer_pbf.get_message()));
-            break;
-        case 5: // extent
-            extent = layer_pbf.get_uint32();
-            break;
-        case 15: // version
-            version = layer_pbf.get_uint32();
-            break;
-        default:
-            layer_pbf.skip();
-            break;
-        }
-    }
-}
-
-util::ptr<const GeometryTileFeature> VectorTileLayer::getFeature(std::size_t i) const {
-    return std::make_shared<VectorTileFeature>(features.at(i), *this);
-}
-
-std::string VectorTileLayer::getName() const {
-    return name;
-}
-
 } // namespace mbgl
diff --git a/src/mbgl/tile/vector_tile_data.cpp b/src/mbgl/tile/vector_tile_data.cpp
new file mode 100644
index 0000000000..fd15dd939d
--- /dev/null
+++ b/src/mbgl/tile/vector_tile_data.cpp
@@ -0,0 +1,218 @@
+#include <mbgl/tile/vector_tile_data.hpp>
+
+namespace mbgl {
+
+class VectorTileLayer;
+
+Value parseValue(protozero::pbf_reader data) {
+    while (data.next()) {
+        switch (data.tag()) {
+        case 1: // string_value
+            return data.get_string();
+        case 2: // float_value
+            return static_cast<double>(data.get_float());
+        case 3: // double_value
+            return data.get_double();
+        case 4: // int_value
+            return data.get_int64();
+        case 5: // uint_value
+            return data.get_uint64();
+        case 6: // sint_value
+            return data.get_sint64();
+        case 7: // bool_value
+            return data.get_bool();
+        default:
+            data.skip();
+            break;
+        }
+    }
+    return false;
+}
+
+VectorTileFeature::VectorTileFeature(protozero::pbf_reader feature_pbf,
+                                     const VectorTileLayer& layer_)
+    : layer(layer_) {
+    while (feature_pbf.next()) {
+        switch (feature_pbf.tag()) {
+        case 1: // id
+            id = { feature_pbf.get_uint64() };
+            break;
+        case 2: // tags
+            tags_iter = feature_pbf.get_packed_uint32();
+            break;
+        case 3: // type
+            type = static_cast<FeatureType>(feature_pbf.get_enum());
+            break;
+        case 4: // geometry
+            geometry_iter = feature_pbf.get_packed_uint32();
+            break;
+        default:
+            feature_pbf.skip();
+            break;
+        }
+    }
+}
+
+optional<Value> VectorTileFeature::getValue(const std::string& key) const {
+    auto keyIter = layer.keysMap.find(key);
+    if (keyIter == layer.keysMap.end()) {
+        return optional<Value>();
+    }
+
+    auto start_itr = tags_iter.first;
+    const auto& end_itr = tags_iter.second;
+    while (start_itr != end_itr) {
+        uint32_t tag_key = static_cast<uint32_t>(*start_itr++);
+
+        if (layer.keysMap.size() <= tag_key) {
+            throw std::runtime_error("feature referenced out of range key");
+        }
+
+        if (start_itr == end_itr) {
+            throw std::runtime_error("uneven number of feature tag ids");
+        }
+
+        uint32_t tag_val = static_cast<uint32_t>(*start_itr++);
+        ;
+        if (layer.values.size() <= tag_val) {
+            throw std::runtime_error("feature referenced out of range value");
+        }
+
+        if (tag_key == keyIter->second) {
+            return layer.values[tag_val];
+        }
+    }
+
+    return optional<Value>();
+}
+
+std::unordered_map<std::string, Value> VectorTileFeature::getProperties() const {
+    std::unordered_map<std::string, Value> properties;
+    auto start_itr = tags_iter.first;
+    const auto& end_itr = tags_iter.second;
+    while (start_itr != end_itr) {
+        uint32_t tag_key = static_cast<uint32_t>(*start_itr++);
+        if (start_itr == end_itr) {
+            throw std::runtime_error("uneven number of feature tag ids");
+        }
+        uint32_t tag_val = static_cast<uint32_t>(*start_itr++);
+        properties[layer.keys.at(tag_key)] = layer.values.at(tag_val);
+    }
+    return properties;
+}
+
+optional<FeatureIdentifier> VectorTileFeature::getID() const {
+    return id;
+}
+
+GeometryCollection VectorTileFeature::getGeometries() const {
+    uint8_t cmd = 1;
+    uint32_t length = 0;
+    int32_t x = 0;
+    int32_t y = 0;
+    const float scale = float(util::EXTENT) / layer.extent;
+
+    GeometryCollection lines;
+
+    lines.emplace_back();
+    GeometryCoordinates* line = &lines.back();
+
+    auto g_itr = geometry_iter;
+    while (g_itr.first != g_itr.second) {
+        if (length == 0) {
+            uint32_t cmd_length = static_cast<uint32_t>(*g_itr.first++);
+            cmd = cmd_length & 0x7;
+            length = cmd_length >> 3;
+        }
+
+        --length;
+
+        if (cmd == 1 || cmd == 2) {
+            x += protozero::decode_zigzag32(static_cast<uint32_t>(*g_itr.first++));
+            y += protozero::decode_zigzag32(static_cast<uint32_t>(*g_itr.first++));
+
+            if (cmd == 1 && !line->empty()) { // moveTo
+                lines.emplace_back();
+                line = &lines.back();
+            }
+
+            line->emplace_back(::round(x * scale), ::round(y * scale));
+
+        } else if (cmd == 7) { // closePolygon
+            if (!line->empty()) {
+                line->push_back((*line)[0]);
+            }
+
+        } else {
+            throw std::runtime_error("unknown command");
+        }
+    }
+
+    if (layer.version >= 2 || type != FeatureType::Polygon) {
+        return lines;
+    }
+
+    return fixupPolygons(lines);
+}
+
+VectorTileData::VectorTileData(std::shared_ptr<const std::string> data_) : data(std::move(data_)) {
+}
+
+util::ptr<GeometryTileLayer> VectorTileData::getLayer(const std::string& name) const {
+    if (!parsed) {
+        parsed = true;
+        protozero::pbf_reader tile_pbf(*data);
+        while (tile_pbf.next(3)) {
+            util::ptr<VectorTileLayer> layer =
+                std::make_shared<VectorTileLayer>(tile_pbf.get_message());
+            layers.emplace(layer->name, layer);
+        }
+    }
+
+    auto layer_it = layers.find(name);
+    if (layer_it != layers.end()) {
+        return layer_it->second;
+    }
+
+    return nullptr;
+}
+
+VectorTileLayer::VectorTileLayer(protozero::pbf_reader layer_pbf) {
+    while (layer_pbf.next()) {
+        switch (layer_pbf.tag()) {
+        case 1: // name
+            name = layer_pbf.get_string();
+            break;
+        case 2: // feature
+            features.push_back(layer_pbf.get_message());
+            break;
+        case 3: // keys
+        {
+            auto iter = keysMap.emplace(layer_pbf.get_string(), keysMap.size());
+            keys.emplace_back(std::reference_wrapper<const std::string>(iter.first->first));
+        } break;
+        case 4: // values
+            values.emplace_back(parseValue(layer_pbf.get_message()));
+            break;
+        case 5: // extent
+            extent = layer_pbf.get_uint32();
+            break;
+        case 15: // version
+            version = layer_pbf.get_uint32();
+            break;
+        default:
+            layer_pbf.skip();
+            break;
+        }
+    }
+}
+
+util::ptr<const GeometryTileFeature> VectorTileLayer::getFeature(std::size_t i) const {
+    return std::make_shared<VectorTileFeature>(features.at(i), *this);
+}
+
+std::string VectorTileLayer::getName() const {
+    return name;
+}
+
+} // namespace mbgl
diff --git a/src/mbgl/tile/vector_tile_data.hpp b/src/mbgl/tile/vector_tile_data.hpp
new file mode 100644
index 0000000000..8c251289a7
--- /dev/null
+++ b/src/mbgl/tile/vector_tile_data.hpp
@@ -0,0 +1,79 @@
+#pragma once
+
+#include <mbgl/tile/geometry_tile_data.hpp>
+
+#include <protozero/pbf_reader.hpp>
+
+#include <functional>
+#include <map>
+#include <string>
+#include <unordered_map>
+#include <utility>
+
+namespace mbgl {
+
+class VectorTileLayer;
+
+namespace {
+
+using pbf_iter_type = protozero::pbf_reader::const_uint32_iterator;
+using packed_iter_type = std::pair<pbf_iter_type, pbf_iter_type>;
+
+} // namespace
+
+class VectorTileFeature : public GeometryTileFeature {
+public:
+    VectorTileFeature(protozero::pbf_reader, const VectorTileLayer&);
+
+    FeatureType getType() const override {
+        return type;
+    }
+    optional<Value> getValue(const std::string&) const override;
+    std::unordered_map<std::string, Value> getProperties() const override;
+    optional<FeatureIdentifier> getID() const override;
+    GeometryCollection getGeometries() const override;
+
+private:
+    const VectorTileLayer& layer;
+    optional<FeatureIdentifier> id;
+    FeatureType type = FeatureType::Unknown;
+    packed_iter_type tags_iter;
+    packed_iter_type geometry_iter;
+};
+
+class VectorTileLayer : public GeometryTileLayer {
+public:
+    VectorTileLayer(protozero::pbf_reader);
+
+    std::size_t featureCount() const override {
+        return features.size();
+    }
+    util::ptr<const GeometryTileFeature> getFeature(std::size_t) const override;
+    std::string getName() const override;
+
+private:
+    friend class VectorTileData;
+    friend class VectorTileFeature;
+
+    std::string name;
+    uint32_t version = 1;
+    uint32_t extent = 4096;
+    std::map<std::string, uint32_t> keysMap;
+    std::vector<std::reference_wrapper<const std::string>> keys;
+    std::vector<Value> values;
+    std::vector<protozero::pbf_reader> features;
+};
+
+class VectorTileData : public GeometryTileData {
+public:
+    VectorTileData(std::shared_ptr<const std::string> data);
+
+    util::ptr<GeometryTileLayer> getLayer(const std::string&) const override;
+
+private:
+    std::shared_ptr<const std::string> data;
+    mutable bool parsed = false;
+    mutable std::map<std::string, util::ptr<GeometryTileLayer>> layers;
+};
+
+} // namespace mbgl
diff --git a/test/fixtures/tile_parser/id:000000,sig:06,src:000000,op:havoc,rep:16 b/test/fixtures/tile_parser/id:000000,sig:06,src:000000,op:havoc,rep:16
new file mode 100644
index 0000000000..ccb7ded269
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000000,sig:06,src:000000,op:havoc,rep:16
@@ -0,0 +1 @@
+Ž
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000001,sig:06,src:000000,op:havoc,rep:8 b/test/fixtures/tile_parser/id:000001,sig:06,src:000000,op:havoc,rep:8
new file mode 100644
index 0000000000..72f454b126
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000001,sig:06,src:000000,op:havoc,rep:8
@@ -0,0 +1 @@
+ñ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000002,sig:06,src:000000,op:havoc,rep:16 b/test/fixtures/tile_parser/id:000002,sig:06,src:000000,op:havoc,rep:16
new file mode 100644
index 0000000000..2af1d37e32
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000002,sig:06,src:000000,op:havoc,rep:16
@@ -0,0 +1 @@
+H½ÿÙƒ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000003,sig:06,src:000000,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000003,sig:06,src:000000,op:havoc,rep:32
new file mode 100644
index 0000000000..41b32e1e23
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000003,sig:06,src:000000,op:havoc,rep:32
@@ -0,0 +1 @@
+°Ã
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000004,sig:06,src:000000,op:havoc,rep:16 b/test/fixtures/tile_parser/id:000004,sig:06,src:000000,op:havoc,rep:16
new file mode 100644
index 0000000000..4da31b8a75
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000004,sig:06,src:000000,op:havoc,rep:16
@@ -0,0 +1 @@
+òò"
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000005,sig:06,src:000000,op:havoc,rep:2 b/test/fixtures/tile_parser/id:000005,sig:06,src:000000,op:havoc,rep:2
new file mode 100644
index 0000000000..33a597e73f
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000005,sig:06,src:000000,op:havoc,rep:2
@@ -0,0 +1 @@
+ý
Ñ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000006,sig:06,src:000000,op:havoc,rep:64 b/test/fixtures/tile_parser/id:000006,sig:06,src:000000,op:havoc,rep:64
new file mode 100644
index 0000000000..c96ab3cc70
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000006,sig:06,src:000000,op:havoc,rep:64
@@ -0,0 +1 @@
+
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000007,sig:06,src:000000,op:havoc,rep:2 b/test/fixtures/tile_parser/id:000007,sig:06,src:000000,op:havoc,rep:2
new file mode 100644
index 0000000000..ca0aef5fc6
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000007,sig:06,src:000000,op:havoc,rep:2
@@ -0,0 +1 @@
+î/
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000008,sig:06,src:000000,op:havoc,rep:16 b/test/fixtures/tile_parser/id:000008,sig:06,src:000000,op:havoc,rep:16
new file mode 100644
index 0000000000..86d54ed2f7
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000008,sig:06,src:000000,op:havoc,rep:16
diff --git a/test/fixtures/tile_parser/id:000009,sig:06,src:000000,op:havoc,rep:8 b/test/fixtures/tile_parser/id:000009,sig:06,src:000000,op:havoc,rep:8
new file mode 100644
index 0000000000..f88e12bd45
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000009,sig:06,src:000000,op:havoc,rep:8
diff --git a/test/fixtures/tile_parser/id:000010,sig:06,src:000000,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000010,sig:06,src:000000,op:havoc,rep:32
new file mode 100644
index 0000000000..501a6bbaf1
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000010,sig:06,src:000000,op:havoc,rep:32
@@ -0,0 +1 @@
+	
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000011,sig:06,src:000000,op:havoc,rep:8 b/test/fixtures/tile_parser/id:000011,sig:06,src:000000,op:havoc,rep:8
new file mode 100644
index 0000000000..34931bd1f2
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000011,sig:06,src:000000,op:havoc,rep:8
diff --git a/test/fixtures/tile_parser/id:000012,sig:06,src:000000,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000012,sig:06,src:000000,op:havoc,rep:32
new file mode 100644
index 0000000000..241bb5b843
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000012,sig:06,src:000000,op:havoc,rep:32
@@ -0,0 +1 @@
+ÿçþ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000013,sig:06,src:000000,op:havoc,rep:8 b/test/fixtures/tile_parser/id:000013,sig:06,src:000000,op:havoc,rep:8
new file mode 100644
index 0000000000..2a6d94d76f
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000013,sig:06,src:000000,op:havoc,rep:8
@@ -0,0 +1 @@
+

ï
dÍÍ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000014,sig:06,src:000000,op:havoc,rep:128 b/test/fixtures/tile_parser/id:000014,sig:06,src:000000,op:havoc,rep:128
new file mode 100644
index 0000000000..5cd97c70df
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000014,sig:06,src:000000,op:havoc,rep:128
@@ -0,0 +1 @@
+ÿÿ=ÿÿÿÿÿÿÿÿ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000015,sig:06,src:000000,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000015,sig:06,src:000000,op:havoc,rep:32
new file mode 100644
index 0000000000..ba5099443d
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000015,sig:06,src:000000,op:havoc,rep:32
diff --git a/test/fixtures/tile_parser/id:000016,sig:06,src:000000,op:havoc,rep:2 b/test/fixtures/tile_parser/id:000016,sig:06,src:000000,op:havoc,rep:2
new file mode 100644
index 0000000000..21ade492ec
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000016,sig:06,src:000000,op:havoc,rep:2
diff --git a/test/fixtures/tile_parser/id:000017,sig:06,src:000000,op:havoc,rep:8 b/test/fixtures/tile_parser/id:000017,sig:06,src:000000,op:havoc,rep:8
new file mode 100644
index 0000000000..116343b772
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000017,sig:06,src:000000,op:havoc,rep:8
@@ -0,0 +1 @@
+ çÑÕÑÑÛÑ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000018,sig:06,src:000000,op:havoc,rep:128 b/test/fixtures/tile_parser/id:000018,sig:06,src:000000,op:havoc,rep:128
new file mode 100644
index 0000000000..343c691276
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000018,sig:06,src:000000,op:havoc,rep:128
@@ -0,0 +1 @@
+5*ÌÌÌÌ*ÌÌÌÌÌÌ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000019,sig:06,src:000000,op:havoc,rep:8 b/test/fixtures/tile_parser/id:000019,sig:06,src:000000,op:havoc,rep:8
new file mode 100644
index 0000000000..3d36333ec4
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000019,sig:06,src:000000,op:havoc,rep:8
diff --git a/test/fixtures/tile_parser/id:000020,sig:06,src:000000,op:havoc,rep:16 b/test/fixtures/tile_parser/id:000020,sig:06,src:000000,op:havoc,rep:16
new file mode 100644
index 0000000000..37bed93971
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000020,sig:06,src:000000,op:havoc,rep:16
diff --git a/test/fixtures/tile_parser/id:000021,sig:06,src:000000,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000021,sig:06,src:000000,op:havoc,rep:32
new file mode 100644
index 0000000000..f64e344494
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000021,sig:06,src:000000,op:havoc,rep:32
diff --git a/test/fixtures/tile_parser/id:000022,sig:06,src:000000,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000022,sig:06,src:000000,op:havoc,rep:32
new file mode 100644
index 0000000000..a952b2e8a2
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000022,sig:06,src:000000,op:havoc,rep:32
diff --git a/test/fixtures/tile_parser/id:000023,sig:06,src:000010,op:arith8,pos:2,val:-2 b/test/fixtures/tile_parser/id:000023,sig:06,src:000010,op:arith8,pos:2,val:-2
new file mode 100644
index 0000000000..d9c34ae208
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000023,sig:06,src:000010,op:arith8,pos:2,val:-2
@@ -0,0 +1 @@
+þ
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000024,sig:06,src:000010,op:arith8,pos:2,val:-3 b/test/fixtures/tile_parser/id:000024,sig:06,src:000010,op:arith8,pos:2,val:-3
new file mode 100644
index 0000000000..fc3a9a4aac
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000024,sig:06,src:000010,op:arith8,pos:2,val:-3
@@ -0,0 +1 @@
+ý
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000025,sig:06,src:000010,op:arith8,pos:2,val:-4 b/test/fixtures/tile_parser/id:000025,sig:06,src:000010,op:arith8,pos:2,val:-4
new file mode 100644
index 0000000000..392605a5d3
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000025,sig:06,src:000010,op:arith8,pos:2,val:-4
@@ -0,0 +1 @@
+ü
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000026,sig:06,src:000010,op:arith8,pos:2,val:+9 b/test/fixtures/tile_parser/id:000026,sig:06,src:000010,op:arith8,pos:2,val:+9
new file mode 100644
index 0000000000..97a3f5edc5
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000026,sig:06,src:000010,op:arith8,pos:2,val:+9
@@ -0,0 +1 @@
+	
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000027,sig:06,src:000010,op:arith8,pos:2,val:+17 b/test/fixtures/tile_parser/id:000027,sig:06,src:000010,op:arith8,pos:2,val:+17
new file mode 100644
index 0000000000..fbe476b76e
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000027,sig:06,src:000010,op:arith8,pos:2,val:+17
@@ -0,0 +1 @@
+
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000028,sig:06,src:000010,op:arith8,pos:2,val:+25 b/test/fixtures/tile_parser/id:000028,sig:06,src:000010,op:arith8,pos:2,val:+25
new file mode 100644
index 0000000000..a5edb71521
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000028,sig:06,src:000010,op:arith8,pos:2,val:+25
@@ -0,0 +1 @@
+
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000029,sig:06,src:000010,op:arith8,pos:2,val:+33 b/test/fixtures/tile_parser/id:000029,sig:06,src:000010,op:arith8,pos:2,val:+33
new file mode 100644
index 0000000000..0c081621a7
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000029,sig:06,src:000010,op:arith8,pos:2,val:+33
@@ -0,0 +1 @@
+!
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000030,sig:06,src:000019,op:havoc,rep:8 b/test/fixtures/tile_parser/id:000030,sig:06,src:000019,op:havoc,rep:8
new file mode 100644
index 0000000000..f85cc81fa2
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000030,sig:06,src:000019,op:havoc,rep:8
diff --git a/test/fixtures/tile_parser/id:000031,sig:06,src:000018,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000031,sig:06,src:000018,op:havoc,rep:32
new file mode 100644
index 0000000000..0150b53f47
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000031,sig:06,src:000018,op:havoc,rep:32
@@ -0,0 +1 @@
+èÓèèèèèèÿú€Øú
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000032,sig:06,src:000026,op:havoc,rep:128 b/test/fixtures/tile_parser/id:000032,sig:06,src:000026,op:havoc,rep:128
new file mode 100644
index 0000000000..9f46944a55
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000032,sig:06,src:000026,op:havoc,rep:128
diff --git a/test/fixtures/tile_parser/id:000033,sig:06,src:000001,op:havoc,rep:32 b/test/fixtures/tile_parser/id:000033,sig:06,src:000001,op:havoc,rep:32
new file mode 100644
index 0000000000..6a1ad321e3
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000033,sig:06,src:000001,op:havoc,rep:32
diff --git a/test/fixtures/tile_parser/id:000034,sig:06,src:000018+000004,op:splice,rep:32 b/test/fixtures/tile_parser/id:000034,sig:06,src:000018+000004,op:splice,rep:32
new file mode 100644
index 0000000000..fb9809d832
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000034,sig:06,src:000018+000004,op:splice,rep:32
diff --git a/test/fixtures/tile_parser/id:000035,sig:06,src:000007+000004,op:splice,rep:4 b/test/fixtures/tile_parser/id:000035,sig:06,src:000007+000004,op:splice,rep:4
new file mode 100644
index 0000000000..2663ab2909
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000035,sig:06,src:000007+000004,op:splice,rep:4
@@ -0,0 +1 @@
+@
\ No newline at end of file
diff --git a/test/fixtures/tile_parser/id:000036,sig:06,src:000040+000043,op:splice,rep:8 b/test/fixtures/tile_parser/id:000036,sig:06,src:000040+000043,op:splice,rep:8
new file mode 100644
index 0000000000..dd9c1f152b
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000036,sig:06,src:000040+000043,op:splice,rep:8
diff --git a/test/fixtures/tile_parser/id:000037,sig:06,src:000044,op:havoc,rep:2 b/test/fixtures/tile_parser/id:000037,sig:06,src:000044,op:havoc,rep:2
new file mode 100644
index 0000000000..6f8c364dd8
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000037,sig:06,src:000044,op:havoc,rep:2
diff --git a/test/fixtures/tile_parser/id:000038,sig:06,src:000002+000010,op:splice,rep:2 b/test/fixtures/tile_parser/id:000038,sig:06,src:000002+000010,op:splice,rep:2
new file mode 100644
index 0000000000..3e1b32aa0a
--- /dev/null
+++ b/test/fixtures/tile_parser/id:000038,sig:06,src:000002+000010,op:splice,rep:2
diff --git a/test/fuzz-input/canonicalize-tile-url/access_token b/test/fuzz-input/canonicalize-tile-url/access_token
new file mode 100644
index 0000000000..73047054cd
--- /dev/null
+++ b/test/fuzz-input/canonicalize-tile-url/access_token
@@ -0,0 +1 @@
+http://api.mapbox.com/v4/a.b/{z}/{x}/{y}.vector.pbf?access_token=key
\ No newline at end of file
diff --git a/test/fuzz-input/canonicalize-tile-url/image b/test/fuzz-input/canonicalize-tile-url/image
new file mode 100644
index 0000000000..8497f1fd9b
--- /dev/null
+++ b/test/fuzz-input/canonicalize-tile-url/image
@@ -0,0 +1 @@
+http://api.mapbox.com/v4/a.b/{z}/{x}/{y}.png
\ No newline at end of file
diff --git a/test/fuzz-input/glyphs-url/boxmap b/test/fuzz-input/glyphs-url/boxmap
new file mode 100644
index 0000000000..84bafe746c
--- /dev/null
+++ b/test/fuzz-input/glyphs-url/boxmap
@@ -0,0 +1 @@
+mapbox://fonts/boxmap/{fontstack}/{range}.pbf
\ No newline at end of file
diff --git a/test/fuzz-input/glyphs-url/comic-sans b/test/fuzz-input/glyphs-url/comic-sans
new file mode 100644
index 0000000000..7e4b223250
--- /dev/null
+++ b/test/fuzz-input/glyphs-url/comic-sans
@@ -0,0 +1 @@
+mapbox://fonts/boxmap/Comic%20Sans/0-255.pbf
\ No newline at end of file
diff --git a/test/fuzz-input/parse-filter/all-in-class.json b/test/fuzz-input/parse-filter/all-in-class.json
new file mode 100644
index 0000000000..02a2ca761d
--- /dev/null
+++ b/test/fuzz-input/parse-filter/all-in-class.json
@@ -0,0 +1 @@
+["all",["in","class","path"]]
\ No newline at end of file
diff --git a/test/fuzz-input/parse-filter/f-gte-array.json b/test/fuzz-input/parse-filter/f-gte-array.json
new file mode 100644
index 0000000000..f04d09b867
--- /dev/null
+++ b/test/fuzz-input/parse-filter/f-gte-array.json
@@ -0,0 +1 @@
+[">=", "f", []]
\ No newline at end of file
diff --git a/test/fuzz-input/parse-filter/has-foo.json b/test/fuzz-input/parse-filter/has-foo.json
new file mode 100644
index 0000000000..37c94d6003
--- /dev/null
+++ b/test/fuzz-input/parse-filter/has-foo.json
@@ -0,0 +1 @@
+["has", "foo"]
\ No newline at end of file
diff --git a/test/fuzz-input/parse-filter/id-lte-4.json b/test/fuzz-input/parse-filter/id-lte-4.json
new file mode 100644
index 0000000000..23fc29c020
--- /dev/null
+++ b/test/fuzz-input/parse-filter/id-lte-4.json
@@ -0,0 +1 @@
+["<=", "$id", 4]
\ No newline at end of file
diff --git a/test/fuzz-input/parse-style/empty.json b/test/fuzz-input/parse-style/empty.json
new file mode 100644
index 0000000000..222ac82bf8
--- /dev/null
+++ b/test/fuzz-input/parse-style/empty.json
@@ -0,0 +1,31 @@
+{
+  "version": 8,
+  "name": "Empty",
+  "sources": {
+    "mapbox": {
+      "type": "vector",
+      "maxzoom": 15,
+      "tiles": [
+        "./fixtures/tiles/{z}-{x}-{y}.vector.pbf"
+      ]
+    }
+  },
+  "layers": [
+    {
+      "id": "background",
+      "type": "background",
+      "paint": {
+        "background-color": "white"
+      }
+    },
+    {
+      "id": "water",
+      "type": "fill",
+      "source": "mapbox",
+      "source-layer": "water",
+      "paint": {
+        "fill-color": "blue"
+      }
+    }
+  ]
+}
diff --git a/test/fuzz-input/parse-tile/0-0-0.vector.pbf b/test/fuzz-input/parse-tile/0-0-0.vector.pbf
new file mode 100644
index 0000000000..a0f049ad43
--- /dev/null
+++ b/test/fuzz-input/parse-tile/0-0-0.vector.pbf
diff --git a/test/fuzz-input/source-url/user.map b/test/fuzz-input/source-url/user.map
new file mode 100644
index 0000000000..33dedc50b8
--- /dev/null
+++ b/test/fuzz-input/source-url/user.map
@@ -0,0 +1 @@
+mapbox://user.map
\ No newline at end of file
diff --git a/test/fuzz-input/sprite-url/streets-draft-png b/test/fuzz-input/sprite-url/streets-draft-png
new file mode 100644
index 0000000000..f7ab08129b
--- /dev/null
+++ b/test/fuzz-input/sprite-url/streets-draft-png
@@ -0,0 +1 @@
+mapbox://sprites/mapbox/streets-v8/draft.png
\ No newline at end of file
diff --git a/test/fuzz-input/sprite-url/streets-json b/test/fuzz-input/sprite-url/streets-json
new file mode 100644
index 0000000000..b58e7e9e78
--- /dev/null
+++ b/test/fuzz-input/sprite-url/streets-json
@@ -0,0 +1 @@
+mapbox://sprites/mapbox/streets-v8.json
\ No newline at end of file
diff --git a/test/fuzz-input/sprite-url/streets-png b/test/fuzz-input/sprite-url/streets-png
new file mode 100644
index 0000000000..f05374a98c
--- /dev/null
+++ b/test/fuzz-input/sprite-url/streets-png
@@ -0,0 +1 @@
+mapbox://sprites/mapbox/streets-v8@2x.png
\ No newline at end of file
diff --git a/test/src/fuzz.cpp b/test/src/fuzz.cpp
new file mode 100644
index 0000000000..b498bc5b48
--- /dev/null
+++ b/test/src/fuzz.cpp
@@ -0,0 +1,90 @@
+#include <mbgl/platform/log.hpp>
+#include <mbgl/style/parser.hpp>
+#include <mbgl/util/mapbox.hpp>
+#include <mbgl/tile/vector_tile_data.hpp>
+
+#include <mbgl/style/rapidjson_conversion.hpp>
+
+#include <mbgl/style/conversion.hpp>
+#include <mbgl/style/conversion/filter.hpp>
+
+#include <protozero/exception.hpp>
+
+#include <iostream>
+#include <istream>
+#include <iterator>
+#include <ostream>
+#include <string>
+#include <unordered_map>
+
+typedef void (*Callback)(std::string);
+static const std::unordered_map<std::string, Callback> fuzzers{
+    { "source-url",
+      [](std::string input) { mbgl::util::mapbox::normalizeSourceURL(input, "key"); } },
+    { "style-url", [](std::string input) { mbgl::util::mapbox::normalizeStyleURL(input, "key"); } },
+    { "sprite-url",
+      [](std::string input) { mbgl::util::mapbox::normalizeSpriteURL(input, "key"); } },
+    { "glyphs-url",
+      [](std::string input) { mbgl::util::mapbox::normalizeGlyphsURL(input, "key"); } },
+    { "tile-url", [](std::string input) { mbgl::util::mapbox::normalizeTileURL(input, "key"); } },
+    { "canonicalize-tile-url",
+      [](std::string input) {
+          mbgl::util::mapbox::canonicalizeTileURL(input, mbgl::SourceType::Raster, 42);
+      } },
+    { "parse-style",
+      [](std::string input) {
+          mbgl::style::Parser parser;
+          parser.parse(input);
+      } },
+    { "parse-filter",
+      [](std::string input) {
+          using namespace mbgl;
+          using namespace mbgl::style;
+          rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> document;
+          document.Parse<0>(input.c_str());
+          if (!document.HasParseError()) {
+              conversion::convert<Filter>(document);
+          }
+      } },
+    { "parse-tile",
+      [](std::string input) {
+          mbgl::VectorTileData tile(std::make_shared<const std::string>(std::move(input)));
+          try {
+              tile.getLayer("foo");
+          } catch (protozero::exception& ex) {
+          }
+      } },
+};
+
+void printValidFuzzers() {
+    std::cerr << "Valid fuzzers are:" << std::endl;
+    for (auto& fuzzer : fuzzers) {
+        std::cerr << "  - " << fuzzer.first << std::endl;
+    }
+}
+
+int main(int argc, char* argv[]) {
+    if (argc < 2) {
+        std::cerr << "Usage: fuzz <fuzzers>" << std::endl;
+        printValidFuzzers();
+        return 1;
+    }
+
+    auto it = fuzzers.find(argv[1]);
+    if (it == fuzzers.end()) {
+        std::cerr << "Fuzzer '" << argv[1] << "' does not exist." << std::endl;
+        printValidFuzzers();
+        return 1;
+    }
+
+    // Disables logging
+    mbgl::Log::setObserver(std::make_unique<mbgl::Log::NullObserver>());
+
+    while (__AFL_LOOP(1000)) {
+        // Pass stdin to the function.
+        std::cin >> std::noskipws;
+        it->second({ std::istream_iterator<char>(std::cin), std::istream_iterator<char>() });
+    }
+
+    return 0;
+}
diff --git a/test/test.gypi b/test/test.gypi
index 304e0e9730..48646fe97e 100644
--- a/test/test.gypi
+++ b/test/test.gypi
@@ -60,6 +60,7 @@
         'text/quads.cpp',
 
         'tile/geometry_tile_data.cpp',
+        'tile/vector_tile_data.cpp',
         'tile/tile_id.cpp',
 
         'storage/offline.cpp',
diff --git a/test/tile/vector_tile_data.cpp b/test/tile/vector_tile_data.cpp
new file mode 100644
index 0000000000..28d0e7d8f3
--- /dev/null
+++ b/test/tile/vector_tile_data.cpp
@@ -0,0 +1,39 @@
+#include <mbgl/test/util.hpp>
+
+#include <mbgl/tile/vector_tile_data.hpp>
+#include <mbgl/util/io.hpp>
+
+#include <iostream>
+#include <fstream>
+
+#include <dirent.h>
+
+using namespace mbgl;
+
+typedef std::pair<uint32_t, std::string> Message;
+typedef std::vector<Message> Messages;
+
+class TileParserTest : public ::testing::TestWithParam<std::string> {};
+
+TEST_P(TileParserTest, ParseTile) {
+    const std::string filename = std::string("test/fixtures/tile_parser/") + GetParam();
+
+    VectorTileData tile(std::make_shared<const std::string>(util::read_file(filename)));
+    tile.getLayer("foo");
+}
+
+INSTANTIATE_TEST_CASE_P(TileParser, TileParserTest, ::testing::ValuesIn([] {
+    std::vector<std::string> names;
+
+    const std::string tile_directory = "test/fixtures/tile_parser";
+    DIR *dir = opendir(tile_directory.c_str());
+    if (dir != nullptr) {
+        for (dirent *dp = nullptr; (dp = readdir(dir)) != nullptr;) {
+            names.push_back(dp->d_name);
+        }
+        closedir(dir);
+    }
+
+    EXPECT_GT(names.size(), 0u);
+    return names;
+}()));