diff --git a/js/src/xpconnect/tests/Makefile.in b/js/src/xpconnect/tests/Makefile.in
index 1d380a838663..aa0f4ad7c868 100644
--- a/js/src/xpconnect/tests/Makefile.in
+++ b/js/src/xpconnect/tests/Makefile.in
@@ -38,7 +38,10 @@ LIBS		= \
 		$(NSPR_LIBS) \
 		$(NULL)
 
-TEST_FILES	= $(srcdir)/testxpc.js $(srcdir)/xpctest_echo.js
+TEST_FILES	= $(srcdir)/testxpc.js \
+              $(srcdir)/xpctest_echo.js \
+              $(srcdir)/xpctest_primitives.js
+
 
 include $(topsrcdir)/config/rules.mk
 
diff --git a/js/src/xpconnect/tests/makefile.win b/js/src/xpconnect/tests/makefile.win
index 0bc0927d708a..5857b70af3f4 100644
--- a/js/src/xpconnect/tests/makefile.win
+++ b/js/src/xpconnect/tests/makefile.win
@@ -24,7 +24,11 @@ DIRS	= components
 MAKE_OBJ_TYPE	= EXE
 PROG1 = .\$(OBJDIR)\TestXPC.exe
 PROGRAMS = $(PROG1)
-TESTCASES = testxpc.js simpletest.js xpctest_echo.js
+TESTCASES = \
+            testxpc.js \
+            simpletest.js \
+            xpctest_echo.js \
+            xpctest_primitives.js
 
 LCFLAGS=-DUSE_NSREG -DWIN32_LEAN_AND_MEAN -DJS_THREADSAFE -DJSFILE
 
diff --git a/js/src/xpconnect/tests/xpctest_primitives.js b/js/src/xpconnect/tests/xpctest_primitives.js
new file mode 100644
index 000000000000..7b5794175f01
--- /dev/null
+++ b/js/src/xpconnect/tests/xpctest_primitives.js
@@ -0,0 +1,140 @@
+/*
+* This is a test for the various nsISupports* 'Primitives' wrappers declared
+* in nsISupportsPrimitives.idl. It is a data driven tests - more values can 
+* be added to the table. It creates instances of the 'wrapper' objects, sets 
+* a values and then does a 'Get' of the values and compares that to the 
+* original. It also exercises the 'toString' methods of the wrappers.
+*
+* The table has plugable compare functions to allows for 'equals' methods of
+* comparision and to allow for 'close enough' comparison of floats and doubles
+*/
+
+
+// prefix used by all these progids
+progid_prefix = "component://netscape/";
+
+// an iid to use to test nsISupportsID
+var iface_test = Components.interfaces.nsISupports;
+// the canonical number form for that iid (e.g. {xxx-xxx...})
+var i_str = iface_test.number
+
+// just a flag used to mean 'use the initial value to toString comparisons'
+var same = Object;
+
+// the table of data...
+
+// columns are:
+// 1) progid suffix
+// 2) interface name
+// 3) value
+// 4) string to use to compare for toString ('same' mans use original value)
+// 5) function to use for comparing values (null means use default compare) 
+// 6) function to use for comparing strings (null means use default compare) 
+var data = [
+ ["supports-id"      ,"nsISupportsID"      ,iface_test,i_str ,eqfn  ,  null],
+ ["supports-string"  ,"nsISupportsString"  ,"foo"     ,same  ,null  ,  null],
+ ["supports-wstring" ,"nsISupportsWString" ,"bar"     ,same  ,null  ,  null],
+ ["supports-PRBool"  ,"nsISupportsPRBool"  ,true      ,same  ,null  ,  null],
+ ["supports-PRBool"  ,"nsISupportsPRBool"  ,false     ,same  ,null  ,  null],
+ ["supports-PRUint8" ,"nsISupportsPRUint8" ,7         ,same  ,null  ,  null],
+ ["supports-PRUint16","nsISupportsPRUint16",12345     ,same  ,null  ,  null],
+ ["supports-PRUint32","nsISupportsPRUint32",123456    ,same  ,null  ,  null],
+ ["supports-PRUint64","nsISupportsPRUint64",1234567   ,same  ,null  ,  null],
+ ["supports-PRTime"  ,"nsISupportsPRTime"  ,12345678  ,same  ,null  ,  null],
+ ["supports-char"    ,"nsISupportsChar"    ,'z'       ,same  ,null  ,  null],
+ ["supports-PRInt16" ,"nsISupportsPRInt16" ,-123      ,same  ,null  ,  null],
+ ["supports-PRInt32" ,"nsISupportsPRInt32" ,-3456     ,same  ,null  ,  null],
+ ["supports-PRInt64" ,"nsISupportsPRInt64" ,-1234566  ,same  ,null  ,  null],
+ ["supports-float"   ,"nsISupportsFloat"   , 12.0001  ,same  ,fcmp  ,  fcmp],
+ ["supports-double"  ,"nsISupportsDouble"  , 1.0029202,same  ,fcmp  ,  fcmp],
+];
+
+function println(s)
+{
+    if(typeof(this.document) == "undefined")
+        print(s);
+    else
+        dump(s+"\n");
+}
+
+// use this to see if floats are fairly close
+function fcmp(v1, v2)
+{
+    var f1 = parseFloat(v1);
+    var f2 = parseFloat(v2);
+    var retval = ((f1 - f2) < 0.001) || ((f2 - f1) < 0.001);
+//    if(retval) println(v1+" is close enough to "+v2);
+    return retval;
+}    
+
+function eqfn(v1, v2)
+{
+    return v1.equals(v2);
+}    
+
+function regular_compare(v1, v2)
+{
+    return v1 == v2;    
+}    
+
+function test(progid, iid, d, string_val, val_compare_fn, str_compare_fn)
+{
+    var test1_result;    
+    var test2_result;    
+    var full_progid = progid_prefix+progid;
+//    println("checking... "+progid+" "+iid+ " with "+d);
+    var clazz = Components.classes[full_progid];
+    if(!clazz) {
+        println(progid+ " is not a valid progid");
+        return false;
+    }
+    var v = clazz.createInstance(Components.interfaces[iid])
+    v.data = d;
+
+    if(!val_compare_fn)
+        val_compare_fn = regular_compare;
+
+    if(!str_compare_fn)
+        str_compare_fn = regular_compare;
+
+    test1_result = val_compare_fn(d,v.data);
+
+    if(string_val) {
+        if(string_val == same)
+            test2_result = str_compare_fn(""+v, ""+d);
+        else
+            test2_result = str_compare_fn(""+v, string_val);
+    }
+    else
+        test2_result = true;
+
+    if(!test1_result)
+        println("failed for... "+progid+" with "+d+" returned "+v.data);
+
+    if(!test2_result)
+        println("failed toString for... "+progid+" with "+d+" returned "+""+v);
+
+
+    return test1_result && test2_result;
+}    
+
+var failureCount = 0;
+var exception = null;
+
+try {
+    println("\n\n starting test... \n");
+    for(i = 0; i < data.length; i++) {
+        var r = data[i];
+        if(!test(r[0], r[1], r[2], r[3], r[4], r[5])) {
+            failureCount++ ;
+        }
+    }
+} catch(e) {
+    exception = e;
+    failureCount++ ;
+}    
+
+
+if(exception)
+    println("caught exception... "+exception);
+println("\n"+(failureCount == 0 ? "all tests PASSED" : ""+failureCount+" errors"));