Merge pull request #3 from localstack/dynamodb-condition-expression

Implement dynamodb condition expression
localstack · Oct 19, 2023 · 8169c36 · 8169c36
2 parents b22a67c + 46b82ac
commit 8169c36
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Showing 6 changed files with 325 additions and 112 deletions.
diff --git a/__tests__/__snapshots__/index.test.js.snap b/__tests__/__snapshots__/index.test.js.snap
@@ -258,6 +258,8 @@ exports[`DynamoDB operations replace 1`] = `
 
 exports[`DynamoDB operations updateListItem 1`] = `undefined`;
 
+exports[`Transformations toDynamoDBConditionExpression 1`] = `"{"expression":"(attribute_exists(#id)) AND (#version = :version_eq)","expressionNames":{"#id":"id","#version":"version"},"expressionValues":{":version_eq":{"N":10}}}"`;
+
 exports[`Transformations toDynamoDBFilterMap 1`] = `"{"expression":"(contains(#title,:title_contains))","expressionNames":{"#title":"title"},"expressionValues":{":title_contains":{"S":"Hello World"}}}"`;
 
 exports[`dynamodb helpers s3 objects four parameter function 1`] = `

diff --git a/__tests__/helpers.js b/__tests__/helpers.js
@@ -46,12 +46,15 @@ const runOnAWS = async (s, context) => {
 }
 
 // If TEST_TARGET is AWS_CLOUD then run the check against AWS. Otherwise, run locally.
-export const checkValid = async (s, context) => {
+export const checkValid = async (s, context, postProcess) => {
   let result;
   if (process.env.TEST_TARGET === "AWS_CLOUD") {
     result = await runOnAWS(s, context);
   } else {
     result = eval(s);
   }
+  if (postProcess) {
+    result = postProcess(result);
+  }
   expect(result).toMatchSnapshot();
 }
diff --git a/__tests__/index.test.js b/__tests__/index.test.js
@@ -137,6 +137,34 @@ describe("Transformations", () => {
   test("toDynamoDBFilterMap", async () => {
     await checkValid(`util.transform.toDynamoDBFilterExpression({ "title":{ "contains":"Hello World" } })`);
   });
+
+  test("toDynamoDBConditionExpression", async () => {
+    // attribute keys are not guaranteed to be ordered
+    const postProcess = (result) => {
+
+      const sortObjectByKeys = (obj) => {
+        return Object.keys(obj).sort().reduce(
+          (res, key) => {
+            res[key] = obj[key];
+            return res;
+          },
+          {}
+        );
+      };
+
+      const { expression, expressionNames, expressionValues } = JSON.parse(result);
+      const transformed = {
+        expression,
+        expressionNames: sortObjectByKeys(expressionNames),
+        expressionValues: sortObjectByKeys(expressionValues),
+      };
+      return JSON.stringify(transformed);
+    };
+    await checkValid(`util.transform.toDynamoDBConditionExpression({
+      id: { attributeExists: true },
+      version: { eq: 10 },
+    })`, {}, postProcess);
+  });
 });
 
 describe("DynamoDB operations", () => {

diff --git a/dynamodb-utils.js b/dynamodb-utils.js
@@ -0,0 +1,112 @@
+export const dynamodbUtils = {
+  toDynamoDB: function(value) {
+    if (typeof (value) === "number") {
+      return this.toNumber(value);
+    } else if (typeof (value) === "string") {
+      return this.toString(value);
+    } else if (typeof (value) === "boolean") {
+      return this.toBoolean(value);
+    } else if (typeof (value) === "object") {
+      if (value.length !== undefined) {
+        return this.toList(value);
+      } else {
+        return this.toMap(value);
+      }
+    } else {
+      throw new Error(`Not implemented for ${value}`);
+    }
+  },
+
+  toString: function(value) {
+    if (value === null) { return null; };
+
+    return { S: value };
+  },
+
+  toStringSet: function(value) {
+    if (value === null) { return null; };
+
+    return { SS: value };
+  },
+
+  toNumber: function(value) {
+    if (value === null) { return null; };
+
+    return { N: value };
+  },
+
+  toNumberSet: function(value) {
+    if (value === null) { return null; };
+
+    return { NS: value };
+  },
+
+  toBinary: function(value) {
+    if (value === null) { return null; };
+
+    return { B: value };
+  },
+
+  toBinarySet: function(value) {
+    if (value === null) { return null; };
+
+    return { BS: value };
+  },
+
+  toBoolean: function(value) {
+    if (value === null) { return null; };
+
+    return { BOOL: value };
+  },
+
+  toNull: function() {
+    return { NULL: null };
+  },
+
+  toList: function(values) {
+    let out = [];
+    for (const value of values) {
+      out.push(this.toDynamoDB(value));
+    }
+    return { L: out }
+  },
+
+  toMap: function(mapping) {
+    return { M: this.toMapValues(mapping) };
+  },
+
+  toMapValues: function(mapping) {
+    let out = {};
+    for (const [k, v] of Object.entries(mapping)) {
+      out[k] = this.toDynamoDB(v);
+    }
+    return out;
+  },
+
+  toS3Object: function(key, bucket, region, version) {
+    let payload;
+    if (version === undefined) {
+      payload = {
+        s3: {
+          key,
+          bucket,
+          region,
+        }
+      };
+    } else {
+      payload = {
+        s3: {
+          key,
+          bucket,
+          region,
+          version,
+        }
+      };
+    };
+    return this.toString(JSON.stringify(payload));
+  },
+
+  fromS3ObjectJson: function(value) {
+    throw new Error("not implemented");
+  },
+}
diff --git a/index.js b/index.js
@@ -1,5 +1,8 @@
 import { v4 as uuidv4 } from 'uuid';
 
+import { generateFilterExpression } from "./transform/dynamodb-filter";
+import { dynamodbUtils } from './dynamodb-utils';
+
 const FILTER_CONTAINS = "contains";
 
 export const util = {
@@ -42,117 +45,15 @@ export const util = {
       return JSON.stringify({ expression, expressionNames, expressionValues });
 
     },
-  },
-  dynamodb: {
-    toDynamoDB: function(value) {
-      if (typeof (value) === "number") {
-        return this.toNumber(value);
-      } else if (typeof (value) === "string") {
-        return this.toString(value);
-      } else if (typeof (value) === "boolean") {
-        return this.toBoolean(value);
-      } else if (typeof (value) === "object") {
-        if (value.length !== undefined) {
-          return this.toList(value);
-        } else {
-          return this.toMap(value);
-        }
-      } else {
-        throw new Error(`Not implemented for ${value}`);
-      }
-    },
-
-    toString: function(value) {
-      if (value === null) { return null; };
-
-      return { S: value };
-    },
-
-    toStringSet: function(value) {
-      if (value === null) { return null; };
-
-      return { SS: value };
-    },
-
-    toNumber: function(value) {
-      if (value === null) { return null; };
-
-      return { N: value };
-    },
-
-    toNumberSet: function(value) {
-      if (value === null) { return null; };
-
-      return { NS: value };
-    },
-
-    toBinary: function(value) {
-      if (value === null) { return null; };
-
-      return { B: value };
-    },
-
-    toBinarySet: function(value) {
-      if (value === null) { return null; };
-
-      return { BS: value };
-    },
-
-    toBoolean: function(value) {
-      if (value === null) { return null; };
-
-      return { BOOL: value };
-    },
-
-    toNull: function() {
-      return { NULL: null };
-    },
-
-    toList: function(values) {
-      let out = [];
-      for (const value of values) {
-        out.push(this.toDynamoDB(value));
-      }
-      return { L: out }
-    },
-
-    toMap: function(mapping) {
-      return { M: this.toMapValues(mapping) };
-    },
-
-    toMapValues: function(mapping) {
-      let out = {};
-      for (const [k, v] of Object.entries(mapping)) {
-        out[k] = this.toDynamoDB(v);
-      }
-      return out;
-    },
-
-    toS3Object: function(key, bucket, region, version) {
-      let payload;
-      if (version === undefined) {
-        payload = {
-          s3: {
-            key,
-            bucket,
-            region,
-          }
-        };
-      } else {
-        payload = {
-          s3: {
-            key,
-            bucket,
-            region,
-            version,
-          }
-        };
-      };
-      return this.toString(JSON.stringify(payload));
-    },
-
-    fromS3ObjectJson: function(value) {
-      throw new Error("not implemented");
+    toDynamoDBConditionExpression(condition) {
+      const result = generateFilterExpression(condition);
+      return JSON.stringify({
+        expression: result.expressions.join(' ').trim(),
+        expressionNames: result.expressionNames,
+        // upstream is missing this value: https://github.com/aws-amplify/amplify-cli/blob/5cc1b556d8081421dc68ee264dac02d5660ffee7/packages/amplify-appsync-simulator/src/velocity/util/transform/index.ts#L11
+        expressionValues: result.expressionValues,
+      });
     },
   },
+  dynamodb: dynamodbUtils,
 };