ugly fix for get single/get array

lib/jsonpath.js

@@ -71,17 +71,24 @@ function jsonPath(obj, expr, arg) {
       },
       trace: function(expr, val, path) {
          // no expr to follow? return path and value as the result of this trace branch
-         if (!expr || !expr.length) return [{path: path, value: val}];
+         if (!expr.length) return path.length ? {path: path, value: val} : undefined;
 
          var loc = expr[0], x = expr.slice(1);
          // the parent sel computation is handled in the frame above using the
          // ancestor object of val
-         if (loc === '^') return [{path: push(path, loc), expr: x, parentSelection: true}];
+         if (loc === '^') return path.length ? {path: push(path, loc), expr: x, parentSelection: true} : undefined;
 
          // we need to gather the return value of recursive trace calls in order to
-         // do the parent sel computation
-         var ret = [];
-         function addRet(elems) { ret = ret.concat(elems); }
+         // do the parent sel computation. The "not wrap" special case makes
+         // the whole result computation much more complicated.
+         var ret = P.wrap ? [] : undefined;
+         function addRet(elems) {
+            if (!ret) { ret = elems; return; }
+            if (!elems) return;
+            if (!Array.isArray(elems)) elems = [elems];
+            if (!Array.isArray(ret)) ret = [ret];
+            ret = ret.concat(elems);
+         }
 
          if (val && val.hasOwnProperty(loc)) // simple case, directly follow property
             addRet(P.trace(x, val[loc], push(path, loc)));
@@ -116,9 +123,16 @@ function jsonPath(obj, expr, arg) {
          // we check the resulting values for parent selections. for parent
          // selections we discard the value object and continue the trace with the
          // current val object
+         if (!ret) return ret;
+         if (!Array.isArray(ret)) {
+            return ret.parentSelection ? P.trace(ret.expr, val, ret.path) : ret;
+         }
          return ret.reduce(function(all, ea) {
-            if (!ea.parentSelection) { all.push(ea); return all; }
-            return all.concat(P.trace(ea.expr, val, ea.path));
+            ea = ea.parentSelection ? P.trace(ea.expr, val, ea.path) : ea;
+            if (!ea) return all;
+            if (!Array.isArray(ea)) all.push(ea);
+            else all = all.concat(ea);
+            return all;
          }, []);
       },
       walk: function(loc, expr, val, path, f) {
@@ -161,15 +175,22 @@ function jsonPath(obj, expr, arg) {
    if (expr && obj && (resultType == "value" || resultType == "path")) {
       var exprList = P.normalize(expr);
       if (exprList[0] === "$" && exprList.length > 1) exprList.shift();
-      var result = P.trace(exprList, obj, ["$"]).reduce(function(result, ea) {
-         var valOrPath = ea[resultType];
-         if (P.flatten && valOrPath instanceof Array) {
-            result = result.concat(valOrPath);
-         } else {
-            result.push(valOrPath);
-         }
-         return result;
-      }, []);
+      var result = P.trace(exprList, obj, ["$"]);
+      if (!result) return P.wrap ? [] : false;
+      if (!Array.isArray(result)) {
+         result = result[resultType];
+         if (P.wrap) result = [result];
+      } else {
+         result = result.reduce(function(result, ea) {
+            var valOrPath = ea[resultType];
+            if (P.flatten && valOrPath instanceof Array) {
+               result = result.concat(valOrPath);
+            } else {
+               result.push(valOrPath);
+            }
+            return result;
+         }, []);
+      }
       return result;
    }
 }