expose type converter overrides & warn on giant numeric values

Author: brianc

lib/textParsers.js

@@ -107,12 +107,19 @@ var parseByteA = function(val) {
   }).replace(/\\\\/g, "\\"), "binary");
 }
 
+var maxLen = Number.MAX_VALUE.toString().length
+
 var init = function(register) {
     register(20, parseInt);
     register(21, parseInt);
     register(23, parseInt);
     register(26, parseInt);
-    register(1700, parseFloat);
+    register(1700, function(val){
+      if(val.length > maxLen) {
+        console.warn('WARNING: value %s is longer than max supported numeric value in javascript. Possible data loss', val)
+      }
+      return parseFloat(val);
+    });
     register(700, parseFloat);
     register(701, parseFloat);
     register(16, parseBool);

lib/types.js

@@ -20,6 +20,14 @@ var getTypeParser = function(oid, format) {
   return typeParsers[format][oid] || noParse;
 };
 
+var setTypeParser = function(oid, format, parseFn) {
+  if(typeof format == 'function') {
+    parseFn = format;
+    format = 'text';
+  }
+  typeParsers[format][oid] = parseFn;
+}
+
 textParsers.init(function(oid, converter) {
   typeParsers.text[oid] = function(value) {
     return converter(String(value));
@@ -32,4 +40,5 @@ binaryParsers.init(function(oid, converter) {
 
 module.exports = {
   getTypeParser: getTypeParser,
+  setTypeParser: setTypeParser
 }

script/list-db-types.js

@@ -1,6 +1,6 @@
 var helper = require(__dirname + "/../test/integration/test-helper");
 var pg = helper.pg;
-pg.connect(helper.connectionString(), assert.success(function(client) {
+pg.connect(helper.config, assert.success(function(client) {
   var query = client.query('select oid, typname from pg_type where typtype = \'b\' order by oid');
   query.on('row', console.log);
 }))

test/integration/client/huge-numeric-tests.js

@@ -0,0 +1,21 @@
+var helper = require(__dirname + '/test-helper');
+
+helper.pg.connect(helper.config, assert.success(function(client) {
+  var types = require(__dirname + '/../../../lib/types');
+  //1231 = numericOID
+  types.setTypeParser(1700, function(){
+    return 'yes';
+  })
+  types.setTypeParser(1700, 'binary', function(){
+    return 'yes';
+  })
+  var bignum = '294733346389144765940638005275322203805';
+  client.query('CREATE TEMP TABLE bignumz(id numeric)');
+  client.query('INSERT INTO bignumz(id) VALUES ($1)', [bignum]);
+  client.query('SELECT * FROM bignumz', assert.success(function(result) {
+    assert.equal(result.rows[0].id, 'yes')
+    helper.pg.end();
+  }))
+}));
+
+//custom type converter