feat(compat): take into account native xsd types in "@type" in context

fix digitalbazaar#466

Author: Elodie Thiéblin

lib/compact.js

@@ -9,7 +9,10 @@ const {
   isArray: _isArray,
   isObject: _isObject,
   isString: _isString,
-  isUndefined: _isUndefined
+  isUndefined: _isUndefined,
+  isBoolean,
+  isDouble,
+  isNumber
 } = require('./types');
 
 const {
@@ -38,6 +41,12 @@ const {
   asArray: _asArray,
   compareShortestLeast: _compareShortestLeast
 } = require('./util');
+const {
+  XSD_BOOLEAN,
+  XSD_DOUBLE,
+  XSD_INTEGER,
+  XSD_STRING
+} = require('./constants');
 
 const api = {};
 module.exports = api;
@@ -996,6 +1005,10 @@ api.compactValue = ({activeCtx, activeProperty, value, options}) => {
       if('@direction' in value && value['@direction'] === direction) {
         return value['@value'];
       }
+      if(!('@type' in value) && type === XSD_STRING) {
+        return value['@value'];
+      }
+
     }
 
     // return just the value of @value if all are true:
@@ -1139,6 +1152,7 @@ function _selectTerm(
   prefs.push('@none');
 
   const containerMap = activeCtx.inverse[iri];
+
   for(const container of containers) {
     // if container not available in the map, continue
     if(!(container in containerMap)) {
@@ -1155,6 +1169,32 @@ function _selectTerm(
       // select term
       return typeOrLanguageValueMap[pref];
     }
+
+    // special case of @type from native types in context and no @type and no
+    // @language specified in value
+    if(containerMap[container].hasOwnProperty('@type') &&
+        value !== null &&
+        !value.hasOwnProperty('@type') &&
+        !value.hasOwnProperty('@language')
+    ) {
+      const containerType = containerMap[container]['@type'];
+      const valueLiteralValue = value['@value'];
+      if(isBoolean(valueLiteralValue) &&
+        containerType.hasOwnProperty(XSD_BOOLEAN)
+      ) {
+        return containerType[XSD_BOOLEAN];
+      } else if(isDouble(valueLiteralValue) &&
+      containerType.hasOwnProperty(XSD_DOUBLE)
+      ) {
+        return containerType[XSD_DOUBLE];
+      } else if(isNumber(valueLiteralValue) &&
+      containerType.hasOwnProperty(XSD_INTEGER)
+      ) {
+        return containerType[XSD_INTEGER];
+      } else if(containerType.hasOwnProperty(XSD_STRING)) {
+        return containerType[XSD_STRING];
+      }
+    }
   }
 
   return null;