feat: added marshall / unmarshall for dynamodb fields

blackflux · Feb 23, 2024 · 428de7d · 428de7d
1 parent 9280e5a
commit 428de7d
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Showing 9 changed files with 476 additions and 12 deletions.
diff --git a/src/module/dy/create-model.js b/src/module/dy/create-model.js
@@ -1,4 +1,5 @@
 import get from 'lodash.get';
+import objectScan from 'object-scan';
 import getFirst from './get-first.js';
 import validateKwargs from './validate-kwargs.js';
 
@@ -61,7 +62,12 @@ export default (kwargs) => {
     name,
     timestamps: false,
     attributes: Object.fromEntries(Object.entries(attributes).map(([k, v]) => {
-      const { validate, ...prunedV } = v;
+      const {
+        validate,
+        marshall,
+        unmarshall,
+        ...prunedV
+      } = v;
       if (prunedV.type === 'set' && Array.isArray(prunedV.default) && prunedV.default.length === 0) {
         const { default: _, ...newV } = prunedV;
         return [k, newV];
@@ -110,9 +116,39 @@ export default (kwargs) => {
     BillingMode: 'PAY_PER_REQUEST'
   };
 
+  const generateMrsl = (fn) => {
+    const logic = Object.fromEntries(
+      Object
+        .entries(attributes)
+        .filter(([k, v]) => typeof v?.[fn] === 'function')
+        .map(([k, v]) => [`{[*].${k},${k}}`, v])
+    );
+    return (itemOrItems) => {
+      objectScan(
+        Object.keys(logic),
+        {
+          filterFn: ({
+            parent,
+            property,
+            value,
+            matchedBy
+          }) => {
+            matchedBy.forEach((m) => {
+              // eslint-disable-next-line no-param-reassign
+              parent[property] = logic[m][fn](value);
+            });
+          }
+        }
+      )(itemOrItems);
+      return itemOrItems;
+    };
+  };
+
   return {
     schema,
     table,
-    entity
+    entity,
+    marshall: generateMrsl('marshall'),
+    unmarshall: generateMrsl('unmarshall')
   };
 };
diff --git a/src/module/dy/fns/get-item.js b/src/module/dy/fns/get-item.js
@@ -36,5 +36,5 @@ export default (model, onNotFound_, setDefaults) => async (...args) => {
     .forEach((k) => {
       delete item[k];
     });
-  return item;
+  return model.unmarshall(item);
 };
diff --git a/src/module/dy/fns/query.js b/src/module/dy/fns/query.js
@@ -155,6 +155,9 @@ export default (model, validateSecondaryIndex, setDefaults, getSortKeyByIndex, c
     if (toReturn !== null) {
       Retainer(toReturn)(items);
     }
-    return { items, page };
+    return {
+      items: model.unmarshall(items),
+      page
+    };
   };
 };
diff --git a/src/module/dy/fns/scan.js b/src/module/dy/fns/scan.js
@@ -34,7 +34,9 @@ export default (model, validateSecondaryIndex, setDefaults) => async (...args) =
     entity: model.table.name
   });
   return {
-    items: result.Items.map((item) => setDefaults(item, toReturn)),
+    items: model.unmarshall(
+      result.Items.map((item) => setDefaults(item, toReturn))
+    ),
     ...(result.LastEvaluatedKey === undefined ? {} : { lastEvaluatedKey: result.LastEvaluatedKey })
   };
 };
diff --git a/src/module/dy/util.js b/src/module/dy/util.js
@@ -109,7 +109,7 @@ export default ({
       let result;
       try {
         result = await model.entity[fn](
-          itemRewriterByFn[fn](item),
+          model.marshall(itemRewriterByFn[fn](item)),
           {
             returnValues: 'all_old',
             ...(conditions === null ? {} : { conditions })
@@ -130,7 +130,7 @@ export default ({
       }
       const didNotExist = result.Attributes === undefined;
       const mergedItem = mergeAttributes(
-        (didNotExist || fn === 'put') ? {} : result.Attributes,
+        (didNotExist || fn === 'put') ? {} : model.unmarshall(result.Attributes),
         item
       );
       const resultItem = setDefaults(mergedItem, null);

diff --git a/src/module/dy/validate-kwargs.js b/src/module/dy/validate-kwargs.js
@@ -8,6 +8,8 @@ const schema = Joi.object().keys({
       type: Joi.string().valid('string', 'boolean', 'number', 'list', 'map', 'binary', 'set'),
       partitionKey: Joi.boolean().valid(true).optional(),
       sortKey: Joi.boolean().valid(true).optional(),
+      marshall: Joi.function().arity(1).optional(),
+      unmarshall: Joi.function().arity(1).optional(),
       default: Joi.alternatives().try(
         Joi.string(),
         Joi.number(),

diff --git a/test/module/dy/create-model.spec.js b/test/module/dy/create-model.spec.js
@@ -30,7 +30,7 @@ describe('Testing create-model.js', () => {
       Table,
       Entity
     });
-    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity']);
+    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity', 'marshall', 'unmarshall']);
   });
 
   it('Testing creation without indices', () => {
@@ -45,7 +45,7 @@ describe('Testing create-model.js', () => {
       Table,
       Entity
     });
-    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity']);
+    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity', 'marshall', 'unmarshall']);
   });
 
   it('Testing creation different attribute types', () => {
@@ -61,7 +61,7 @@ describe('Testing create-model.js', () => {
       Table,
       Entity
     });
-    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity']);
+    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity', 'marshall', 'unmarshall']);
   });
 
   it('Testing attribute not supported for indexing error', () => {
@@ -95,6 +95,6 @@ describe('Testing create-model.js', () => {
       Table,
       Entity
     });
-    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity']);
+    expect(Object.keys(r)).to.deep.equal(['schema', 'table', 'entity', 'marshall', 'unmarshall']);
   });
 });
diff --git a/test/module/dy/fns/get-item.spec.js b/test/module/dy/fns/get-item.spec.js
@@ -1,6 +1,7 @@
 import { expect } from 'chai';
 import { describe } from 'node-tdd';
-import { LocalTable, buildModel, createItems } from '../../../dy-helper.js';
+import zlib from 'zlib';
+import { buildModel, createItems, LocalTable } from '../../../dy-helper.js';
 import { ModelNotFound } from '../../../../src/resources/errors.js';
 import nockReqHeaderOverwrite from '../../../req-header-overwrite.js';
 
@@ -99,4 +100,27 @@ describe('Testing get-item', {
     result.ids.push(1, 2, 3);
     expect(def).to.deep.equal([]);
   });
+
+  it('Testing getItem with custom marshalling', async () => {
+    await generateTable({
+      extraAttrs: {
+        bin: {
+          type: 'binary',
+          default: () => [],
+          marshall: (item) => zlib.gzipSync(JSON.stringify(item), { level: 9 }),
+          unmarshall: (item) => JSON.parse(zlib.gunzipSync(item))
+        }
+      }
+    });
+
+    const { item } = await model.create({
+      id: '123',
+      name: 'name',
+      age: 50,
+      bin: [{ a: 1 }]
+    });
+    const key = { id: item.id, name: item.name };
+    const result = await model.getItem(key, { toReturn: ['bin'] });
+    expect(result).to.deep.equal({ bin: [{ a: 1 }] });
+  });
 });