feat(justifications): implement get

Author: epiqueras

serverless.yml

@@ -86,6 +86,18 @@ custom:
           contentType: application/json,
           schema: '${file(src/doges-on-trial/models/doge-images.json):post.response}',
         }
+      - {
+          name: GetJustificationsRequest,
+          description: 'The request for getJustifications.',
+          contentType: application/json,
+          schema: '${file(src/court/models/justifications.json):get.request}',
+        }
+      - {
+          name: GetJustificationsResponse,
+          description: 'The response for getJustifications.',
+          contentType: application/json,
+          schema: '${file(src/court/models/justifications.json):get.response}',
+        }
       - {
           name: PutJustificationsRequest,
           description: 'The request for putJustifications.',
@@ -230,6 +242,32 @@ functions:
             responseModels: { application/json: ErrorResponse },
           },
         ]
+  getJustifications:
+    handler: src/court/justifications.get
+    events:
+      - { http: { path: justifications, method: post, cors: true } }
+    iamRoleStatementsName: 'getJustifications-${self:provider.stage}-lambda-role'
+    iamRoleStatements:
+      - {
+          Effect: Allow,
+          Action: ['dynamodb:Query'],
+          Resource: 'arn:aws:dynamodb:us-east-2:547511976516:table/justifications',
+        }
+    documentation:
+      summary: 'Get justifications for a dispute round.'
+      description: 'Get justifications for a dispute round.'
+      requestModels: { application/json: GetJustificationsRequest }
+      methodResponses:
+        [
+          {
+            statusCode: '200',
+            responseModels: { application/json: GetJustificationsResponse },
+          },
+          {
+            statusCode: '400',
+            responseModels: { application/json: ErrorResponse },
+          },
+        ]
   putJustifications:
     handler: src/court/justifications.put
     events:

src/court/justifications.js

@@ -2,6 +2,28 @@ const _web3 = require('../utils/web3')
 const KlerosLiquid = require('../assets/contracts/KlerosLiquid.json')
 const dynamoDB = require('../utils/dynamo-db')
 
+module.exports.get = async (event, _context, callback) => {
+  // Fetch justifications and return them
+  const payload = JSON.parse(event.body).payload
+  callback(null, {
+    statusCode: 200,
+    headers: { 'Access-Control-Allow-Origin': '*' },
+    body: JSON.stringify({
+      payload: {
+        justifications: await dynamoDB.query({
+          ExpressionAttributeValues: {
+            ':disputeIDAndAppeal': {
+              S: `${payload.disputeID}-${payload.appeal}`
+            }
+          },
+          KeyConditionExpression: 'disputeIDAndAppeal = :disputeIDAndAppeal',
+          TableName: 'justifications'
+        })
+      }
+    })
+  })
+}
+
 module.exports.put = async (event, _context, callback) => {
   // Initialize web3 and contracts
   const web3 = await _web3()

src/court/models/justifications.json

@@ -1,4 +1,38 @@
 {
+  "get": {
+    "request": {
+      "type": "object",
+      "properties": {
+        "payload": {
+          "type": "object",
+          "properties": {
+            "disputeID": {
+              "type": "number",
+              "description": "The ID of the dispute the votes are cast for."
+            },
+            "appeal": {
+              "type": "number",
+              "description": "The appeal of the dispute the votes are cast for."
+            }
+          }
+        }
+      }
+    },
+    "response": {
+      "type": "object",
+      "properties": {
+        "payload": {
+          "type": "object",
+          "properties": {
+            "justifications": {
+              "type": "object",
+              "description": "The justifications query response."
+            }
+          }
+        }
+      }
+    }
+  },
   "put": {
     "request": {
       "type": "object",

src/utils/dynamo-db.js

@@ -6,5 +6,6 @@ const dynamoDB = new DynamoDB({ apiVersion: '2012-08-10', region: 'us-east-2' })
 dynamoDB.getItem = promisify(dynamoDB.getItem)
 dynamoDB.putItem = promisify(dynamoDB.putItem)
 dynamoDB.updateItem = promisify(dynamoDB.updateItem)
+dynamoDB.query = promisify(dynamoDB.query)
 
 module.exports = dynamoDB