From 0406c2719dcbbe8bbd71e3866ad55f79ef98a4fb Mon Sep 17 00:00:00 2001
From: John Firebaugh <john.firebaugh@gmail.com>
Date: Sun, 26 Oct 2014 10:37:03 -0700
Subject: [PATCH] Validate v6 filter syntax (fixes #1)

---
 lib/validate.js                  | 65 +++++++++++++++++++++---
 test/fixture/filters.input.json  | 87 ++++++++++++++++++++++++++++++++
 test/fixture/filters.output.json | 38 ++++++++++++++
 test/fixture/layers.input.json   |  2 +-
 4 files changed, 183 insertions(+), 9 deletions(-)
 create mode 100644 test/fixture/filters.input.json
 create mode 100644 test/fixture/filters.output.json

diff --git a/lib/validate.js b/lib/validate.js
index 18cf39aa4d1..dcf42bfcddb 100644
--- a/lib/validate.js
+++ b/lib/validate.js
@@ -182,8 +182,51 @@ module.exports = function(str) {
         }
     };
 
-    validate.filter = function(/*key, val, spec*/) {
-        // TODO
+    validate.filter = function(key, val) {
+        if (typeof_(val) !== 'array') {
+            return error(key, val, 'array expected, %s found', typeof_(val));
+        }
+
+        if (val.length < 1) {
+            return error(key, val, 'filter array must have at least 1 element');
+        }
+
+        validate.enum(key + '[0]', val[0], reference.filter_operator);
+
+        switch (unbundle(val[0])) {
+            case '==':
+            case '!=':
+            case '<':
+            case '<=':
+            case '>':
+            case '>=':
+                if (val.length != 3) {
+                    error(key, val, 'filter array for operator "%s" must have 3 elements', val[0]);
+                }
+            /* falls through */
+            case 'in':
+            case '!in':
+                if (val.length >= 2) {
+                    validate.string(key + '[1]', val[1]);
+                }
+                for (var i = 2; i < val.length; i++) {
+                    var type = typeof_(val[i]);
+                    if (val[1] == '$type') {
+                        validate.enum(key + '[' + i + ']', val[i], reference.geometry_type);
+                    } else if (type !== 'string' && type !== 'number' && type !== 'boolean') {
+                        error(key + '[' + i + ']', val[i], 'string, number, or boolean expected, %s found', type);
+                    }
+                }
+                break;
+
+            case 'any':
+            case 'all':
+            case 'none':
+                for (i = 1; i < val.length; i++) {
+                    validate.filter(key + '[' + i + ']', val[i]);
+                }
+                break;
+        }
     };
 
     validate.function = function(key, val, spec) {
@@ -220,12 +263,18 @@ module.exports = function(str) {
         }
     };
 
-    validate.number = validate.string = validate.boolean = function(key, val, spec) {
-        var type = typeof_(val);
-        if (type !== spec.type) {
-            error(key, val, '%s expected, %s found', spec.type, type);
-        }
-    };
+    function typeValidator(expected) {
+        return function(key, val) {
+            var actual = typeof_(val);
+            if (actual !== expected) {
+                error(key, val, '%s expected, %s found', expected, actual);
+            }
+        };
+    }
+
+    validate.number = typeValidator('number');
+    validate.string = typeValidator('string');
+    validate.boolean = typeValidator('boolean');
 
     validate['*'] = function() {};
 
diff --git a/test/fixture/filters.input.json b/test/fixture/filters.input.json
new file mode 100644
index 00000000000..13d0b136b10
--- /dev/null
+++ b/test/fixture/filters.input.json
@@ -0,0 +1,87 @@
+{
+  "version": 6,
+  "sources": {
+    "source": {
+      "type": "vector",
+      "url": "mapbox://mapbox.mapbox-streets-v5"
+    }
+  },
+  "layers": [
+    {
+      "id": "not-array",
+      "type": "line",
+      "source": "source",
+      "filter": {}
+    },
+    {
+      "id": "zero-elements",
+      "type": "line",
+      "source": "source",
+      "filter": []
+    },
+    {
+      "id": "invalid-operator",
+      "type": "line",
+      "source": "source",
+      "filter": [
+        "=",
+        "key",
+        "value"
+      ]
+    },
+    {
+      "id": "missing-key",
+      "type": "line",
+      "source": "source",
+      "filter": ["=="]
+    },
+    {
+      "id": "missing-value",
+      "type": "line",
+      "source": "source",
+      "filter": [
+        "==",
+        "key"
+      ]
+    },
+    {
+      "id": "invalid-key",
+      "type": "line",
+      "source": "source",
+      "filter": [
+        "==",
+        1,
+        "value"
+      ]
+    },
+    {
+      "id": "invalid-value",
+      "type": "line",
+      "source": "source",
+      "filter": [
+        "==",
+        "key",
+        []
+      ]
+    },
+    {
+      "id": "invalid-type",
+      "type": "line",
+      "source": "source",
+      "filter": [
+        "==",
+        "$type",
+        "value"
+      ]
+    },
+    {
+      "id": "invalid-nested-filter",
+      "type": "line",
+      "source": "source",
+      "filter": [
+        "any",
+        []
+      ]
+    }
+  ]
+}
diff --git a/test/fixture/filters.output.json b/test/fixture/filters.output.json
new file mode 100644
index 00000000000..35e95a26c4e
--- /dev/null
+++ b/test/fixture/filters.output.json
@@ -0,0 +1,38 @@
+[
+  {
+    "line": 14,
+    "message": "layers[0].filter: array expected, object found"
+  },
+  {
+    "line": 20,
+    "message": "layers[1].filter: filter array must have at least 1 element"
+  },
+  {
+    "line": 27,
+    "message": "layers[2].filter[0]: expected one of [==, !=, >, >=, <, <=, in, !in, all, any, none], = found"
+  },
+  {
+    "line": 36,
+    "message": "layers[3].filter: filter array for operator \"==\" must have 3 elements"
+  },
+  {
+    "line": 42,
+    "message": "layers[4].filter: filter array for operator \"==\" must have 3 elements"
+  },
+  {
+    "line": 53,
+    "message": "layers[5].filter[1]: string expected, number found"
+  },
+  {
+    "line": 64,
+    "message": "layers[6].filter[2]: string, number, or boolean expected, array found"
+  },
+  {
+    "line": 74,
+    "message": "layers[7].filter[2]: expected one of [Point, LineString, Polygon], value found"
+  },
+  {
+    "line": 83,
+    "message": "layers[8].filter[1]: filter array must have at least 1 element"
+  }
+]
\ No newline at end of file
diff --git a/test/fixture/layers.input.json b/test/fixture/layers.input.json
index ab0b5dd68c4..565af6ddc68 100644
--- a/test/fixture/layers.input.json
+++ b/test/fixture/layers.input.json
@@ -27,7 +27,7 @@
       "type": "line",
       "source": "vector",
       "source-layer": "source-layer",
-      "filter": [],
+      "filter": ["any"],
       "render": {}
     },
     {