Ensure no undefines in update requests.

.vscode/settings.json

@@ -2,6 +2,7 @@
     "cSpell.words": [
         "atsquad",
         "cimpress",
+        "clonedeep",
         "Fqdn",
         "microsoftonline",
         "nosniff",

CHANGELOG.md

@@ -1,3 +1,4 @@
 # Change log
 
 ## 1.0 ##
+* Coerce `undefined` expression attribute values to `null`, because dynamoDb can't handle that, and it strips them from the request

package.json

@@ -66,5 +66,8 @@
   "homepage": "https://rhosys.ch",
   "engines": {
     "node": ">=16"
+  },
+  "dependencies": {
+    "lodash.clonedeep": "^4.5.0"
   }
 }

src/dynamoDbSafe.js

@@ -1,4 +1,5 @@
 const DynamoDbOriginal = require('aws-sdk/clients/dynamodb');
+const cloneDeep = require('lodash.clonedeep');
 
 process.env.AWS_NODEJS_CONNECTION_REUSE_ENABLED = 1;
 
@@ -25,6 +26,18 @@ function parseExpression(logger, expression, isMultiExpression) {
 
   return { keys: {}, values: {} };
 }
+
+function coerceExpressionAttributeNamesAndValues(parameters) {
+  const newParameters = cloneDeep(parameters);
+  Object.keys(newParameters.ExpressionAttributeValues || {}).map(key => {
+    if (newParameters.ExpressionAttributeValues[key] === undefined) {
+      newParameters.ExpressionAttributeValues[key] = null;
+    }
+  });
+
+  return newParameters;
+}
+
 class DynamoDB extends DynamoDbOriginal.DocumentClient {
   constructor(args) {
     super(args);
@@ -35,7 +48,7 @@ class DynamoDB extends DynamoDbOriginal.DocumentClient {
     if (!originalParams || !originalParams.TableName) { throw new DynamoDbError({ error: 'TableName not specified', parameters: originalParams }, 'InvalidParameters'); }
     if (!originalParams.Key) { throw new DynamoDbError({ error: 'Key not specified', parameters: originalParams }, 'InvalidParameters'); }
 
-    const params = originalParams;
+    const params = coerceExpressionAttributeNamesAndValues(originalParams);
     const capturedStack = { name: 'DynamoDB.update() Error:' };
     Error.captureStackTrace(capturedStack);
     const resultAsync = super.get(params).promise().catch(error => {
@@ -53,7 +66,7 @@ class DynamoDB extends DynamoDbOriginal.DocumentClient {
     if (!originalParams || !originalParams.TableName) { throw new DynamoDbError({ error: 'TableName not specified', parameters: originalParams }, 'InvalidParameters'); }
     if (!originalParams.KeyConditionExpression) { throw new DynamoDbError({ error: 'KeyConditionExpression not specified', parameters: originalParams }, 'InvalidParameters'); }
 
-    const params = originalParams;
+    const params = coerceExpressionAttributeNamesAndValues(originalParams);
     const capturedStack = { name: 'DynamoDB.update() Error:' };
     Error.captureStackTrace(capturedStack);
     const resultAsync = super.query(params).promise().catch(error => {
@@ -76,7 +89,7 @@ class DynamoDB extends DynamoDbOriginal.DocumentClient {
       // Validate the tokens
     }
 
-    const params = originalParams;
+    const params = coerceExpressionAttributeNamesAndValues(originalParams);
     const capturedStack = { name: 'DynamoDB.update() Error:' };
     Error.captureStackTrace(capturedStack);
     const resultAsync = super.delete(params).promise().catch(error => {
@@ -99,7 +112,7 @@ class DynamoDB extends DynamoDbOriginal.DocumentClient {
       // Validate the tokens
     }
 
-    const params = originalParams;
+    const params = coerceExpressionAttributeNamesAndValues(originalParams);
     const capturedStack = { name: 'DynamoDB.update() Error:' };
     Error.captureStackTrace(capturedStack);
     const resultAsync = super.put(params).promise().catch(error => {
@@ -116,7 +129,7 @@ class DynamoDB extends DynamoDbOriginal.DocumentClient {
   scan(originalParams) {
     if (!originalParams || !originalParams.TableName) { throw new DynamoDbError({ error: 'TableName not specified', parameters: originalParams }, 'InvalidParameters'); }
 
-    const params = originalParams;
+    const params = coerceExpressionAttributeNamesAndValues(originalParams);
     const capturedStack = { name: 'DynamoDB.update() Error:' };
     Error.captureStackTrace(capturedStack);
     const resultAsync = super.scan(params).promise().catch(error => {
@@ -142,7 +155,7 @@ class DynamoDB extends DynamoDbOriginal.DocumentClient {
       // Validate the tokens
     }
 
-    const params = originalParams;
+    const params = coerceExpressionAttributeNamesAndValues(originalParams);
     const capturedStack = { name: 'DynamoDB.update() Error:' };
     Error.captureStackTrace(capturedStack);
     const resultAsync = super.update(params).promise().catch(error => {

tests/attributeNamesAndValues.test.js

@@ -0,0 +1,47 @@
+const { expect } = require('chai');
+const { describe, it, beforeEach, afterEach } = require('mocha');
+const sinon = require('sinon');
+const { DynamoDB: DynamoDbOriginal } = require('aws-sdk');
+
+let sandbox;
+beforeEach(() => { sandbox = sinon.createSandbox(); });
+afterEach(() => sandbox.restore());
+
+const { DynamoDB } = require('../src/dynamoDbSafe');
+const cloneDeep = require('lodash.clonedeep');
+
+describe('dynamoDbArmor.js', () => {
+  describe('namesAndValuesCoercion()', () => {
+    it('Fixes undefined expressionAttributeValue - Coerce `undefined` expression attribute values to `null`, because dynamoDb cant handle them, and it strips them from the request. nulls are not stripped', async () => {
+      const testTable = 'Test-TableId';
+      const testHash = 'testHash';
+      const testRange = 'testRange';
+      const params = {
+        TableName: testTable,
+        Key: {
+          hash: testHash,
+          rang: testRange
+        },
+        UpdateExpression: 'SET #key = :value',
+        ConditionExpression: 'attribute_exists(hash)',
+        ExpressionAttributeNames: {
+          '#key': 'key'
+        },
+        ExpressionAttributeValues: {
+          ':value': undefined
+        }
+      };
+      try {
+        const dynamoDbOriginalMock = sandbox.mock(DynamoDbOriginal.DocumentClient.prototype);
+
+        const expectedParams = cloneDeep(params);
+        expectedParams.ExpressionAttributeValues[':value'] = null;
+        dynamoDbOriginalMock.expects('update').once().withArgs(expectedParams).returns({ promise() { return Promise.resolve(); } });
+        await new DynamoDB().update(params);
+        dynamoDbOriginalMock.verify();
+      } catch (error) {
+        expect(error.message).to.eql(null, JSON.stringify(error.message, null, 2));
+      }
+    });
+  });
+});

yarn.lock

@@ -2619,7 +2619,7 @@ locate-path@^6.0.0:
 lodash.clonedeep@^4.5.0:
   version "4.5.0"
   resolved "https://registry.yarnpkg.com/lodash.clonedeep/-/lodash.clonedeep-4.5.0.tgz#e23f3f9c4f8fbdde872529c1071857a086e5ccef"
-  integrity sha1-4j8/nE+Pvd6HJSnBBxhXoIblzO8=
+  integrity sha512-H5ZhCF25riFd9uB5UCkVKo61m3S/xZk1x4wA6yp/L3RFP6Z/eHH1ymQcGLo7J3GMPfm0V/7m1tryHuGVxpqEBQ==
 
 lodash.defaults@^4.2.0:
   version "4.2.0"