utils: persist values right after selection

With this, we can avoid a second run of fields selection,
therefore a sanitizer won't run twice.

Fixes #572, fixes #584

check/check.js

@@ -2,7 +2,6 @@ const validator = require('validator');
 
 const runner = require('./runner');
 const { isSanitizer, isValidator } = require('../utils/filters');
-const persistValues = require('../utils/persist-values');
 
 module.exports = (fields, locations, message) => {
   let optional;
@@ -14,7 +13,6 @@ module.exports = (fields, locations, message) => {
     return runner(req, middleware._context).then(errors => {
       req._validationContexts = (req._validationContexts || []).concat(middleware._context);
       req._validationErrors = (req._validationErrors || []).concat(errors);
-      persistValues(req, middleware._context);
       next();
     }, next);
   };

check/one-of.js

@@ -1,5 +1,4 @@
 const _ = require('lodash');
-const persistValues = require('../utils/persist-values');
 const runner = require('./runner');
 
 module.exports = (validationChains, message) => (req, res, next) => {
@@ -30,7 +29,6 @@ module.exports = (validationChains, message) => (req, res, next) => {
       });
     }
 
-    contexts.forEach(context => persistValues(req, context));
     next();
     return results;
   }).catch(next);

filter/sanitize.js

@@ -1,14 +1,14 @@
 const validator = require('validator');
 
 const { isSanitizer } = require('../utils/filters');
-const persistValues = require('../utils/persist-values');
+const selectFields = require('../utils/select-fields');
 
 module.exports = (fields, locations) => {
   const sanitizers = [];
   fields = Array.isArray(fields) ? fields : [fields];
 
   const middleware = (req, res, next) => {
-    persistValues(req, { fields, locations, sanitizers });
+    selectFields(req, { fields, locations, sanitizers });
     next();
   };
 

utils/persist-values.js

@@ -1,8 +1,7 @@
 const _ = require('lodash');
-const selectFields = require('./select-fields');
 
-module.exports = (req, context) => {
-  selectFields(req, context).filter(instance => {
+module.exports = (req, fieldInstances) => {
+  fieldInstances.filter(instance => {
     const initialValue = _.get(req[instance.location], instance.path);
     return initialValue !== instance.value;
   }).forEach(instance => {

utils/persist-values.spec.js

@@ -2,20 +2,16 @@ const { expect } = require('chai');
 const persistValues = require('./persist-values');
 
 describe('utils: persistValues', () => {
-  it('persists selected fields back into req', () => {
+  it('persists a list of fields back into req', () => {
     const req = {
       query: { foo: ' bar ' },
       body: { bar: { baz: ' qux ' } }
     };
 
-    persistValues(req, {
-      fields: ['foo', 'bar.baz'],
-      locations: ['query', 'body'],
-      sanitizers: [{
-        options: [],
-        sanitizer: value => value.trim()
-      }]
-    });
+    persistValues(req, [
+      { location: 'query', path: 'foo', value: 'bar' },
+      { location: 'body', path: 'bar.baz', value: 'qux' },
+    ]);
 
     expect(req.query.foo).to.equal('bar');
     expect(req.body.bar.baz).to.equal('qux');
@@ -26,10 +22,9 @@ describe('utils: persistValues', () => {
       query: {}
     };
 
-    persistValues(req, {
-      fields: ['foo'],
-      locations: ['query']
-    });
+    persistValues(req, [
+      { location: 'query', path: 'foo', value: undefined },
+    ]);
 
     expect(req.query).not.to.have.key('foo');
   });

utils/select-fields.js

@@ -1,5 +1,6 @@
 const _ = require('lodash');
 const formatParamOutput = require('./format-param-output');
+const persistValues = require('./persist-values');
 
 module.exports = (req, context, options = {}) => {
   let allFields = [];
@@ -27,6 +28,7 @@ module.exports = (req, context, options = {}) => {
     allFields = allFields.concat(instances);
   });
 
+  persistValues(req, allFields);
   return _.uniqWith(allFields, _.isEqual);
 };
 

utils/select-fields.spec.js

@@ -144,6 +144,20 @@ describe('utils: selectFields', () => {
     });
   })
 
+  it('persists values right after selection', () => {
+    const req = {
+      body: { foo: 'a' }
+    };
+
+    selectFields(req, {
+      fields: ['foo'],
+      locations: ['body'],
+      sanitizers: [{ sanitizer: value => value.toUpperCase(), options: [] }]
+    });
+
+    expect(req.body.foo).to.equal('A');
+  });
+
   describe('sanitization', () => {
     it('runs on the selected values', () => {
       const req = {