New: Added 'json' conversion option for proto3 JSON mapping compatibi…

…lity of NaN and Infinity + additional documentation of util.toJSONOptions, see #351

README.md

@@ -570,7 +570,7 @@ Supported decorators are:
 * **OneOf.d&lt;T extends string>(...fieldNames: `string[]`)**<br />
   annotates a property as a protobuf oneof covering the specified fields.
 
-Decorated types reside in `protobuf.roots.decorators` using a flat structure (no duplicate names).
+Decorated types reside in `protobuf.roots["decorators"]` using a flat structure (no duplicate names).
 
 Command line
 ------------

src/converter.js

@@ -40,8 +40,8 @@ function genValuePartial_fromObject(gen, field, fieldIndex, prop) {
         var isUnsigned = false;
         switch (field.type) {
             case "double":
-            case "float":gen
-                ("m%s=Number(d%s)", prop, prop);
+            case "float": gen
+                ("m%s=Number(d%s)", prop, prop); // also catches "NaN", "Infinity"
                 break;
             case "uint32":
             case "fixed32": gen
@@ -162,6 +162,10 @@ function genValuePartial_toObject(gen, field, fieldIndex, prop) {
     } else {
         var isUnsigned = false;
         switch (field.type) {
+            case "double":
+            case "float": gen
+            ("d%s=o.json&&!isFinite(m%s)?String(m%s):m%s", prop, prop, prop, prop);
+                break;
             case "uint64":
                 isUnsigned = true;
                 // eslint-disable-line no-fallthrough

src/type.js

@@ -537,6 +537,7 @@ Type.prototype.fromObject = function fromObject(object) {
  * @property {boolean} [arrays=false] Sets empty arrays for missing repeated fields even if `defaults=false`
  * @property {boolean} [objects=false] Sets empty objects for missing map fields even if `defaults=false`
  * @property {boolean} [oneofs=false] Includes virtual oneof properties set to the present field's name, if any
+ * @property {boolean} [json=false] Performs additional JSON compatibility conversions, i.e. NaN and Infinity to strings
  */
 
 /**

src/util/minimal.js

@@ -375,13 +375,26 @@ util.oneOfSetter = function setOneOf(fieldNames) {
 };
 
 /**
- * Default conversion options used for {@link Message#toJSON} implementations. Longs, enums and bytes are converted to strings by default.
+ * Default conversion options used for {@link Message#toJSON} implementations.
+ * 
+ * These options are close to proto3's JSON mapping with the exception that internal types like Any are handled just like messages. More precisely:
+ * 
+ * - Longs become strings
+ * - Enums become string keys
+ * - Bytes become base64 encoded strings
+ * - (Sub-)Messages become plain objects
+ * - Maps become plain objects with all string keys
+ * - Repeated fields become arrays
+ * - NaN and Infinity for float and double fields become strings
+ * 
  * @type {ConversionOptions}
+ * @see https://developers.google.com/protocol-buffers/docs/proto3?hl=en#json
  */
 util.toJSONOptions = {
     longs: String,
     enums: String,
-    bytes: String
+    bytes: String,
+    json: true
 };
 
 util._configure = function() {