Feat: As a user, I want to know how many attestations were issued thr…

…ough a given Schema (#543)

subgraph/schema.graphql

@@ -40,6 +40,7 @@ type Schema @entity {
   description: String!
   context: String!
   schema: String!
+  attestationCounter: Int
 }
 
 type Counter @entity {

subgraph/src/attestation-registry.ts

@@ -13,7 +13,7 @@ export function handleAttestationRegistered(event: AttestationRegisteredEvent):
   const attestationData = attestationRegistryContract.getAttestation(event.params.attestationId);
   const attestation = new Attestation(event.params.attestationId.toHex());
 
-  incrementAttestationCount(attestationData.portal.toHexString());
+  incrementAttestationCount(attestationData.portal.toHexString(), attestationData.schemaId.toHex());
 
   attestation.schemaId = attestationData.schemaId;
   attestation.replacedBy = attestationData.replacedBy;
@@ -157,7 +157,7 @@ function valueToString(value: ethereum.Value): string {
   }
 }
 
-function incrementAttestationCount(portalAddress: string): void {
+function incrementAttestationCount(portalAddress: string, schemaId: string): void {
   let counter = Counter.load("counter");
 
   if (!counter) {
@@ -184,4 +184,17 @@ function incrementAttestationCount(portalAddress: string): void {
 
     portal.save();
   }
+
+  // Increment attestation counter for corresponding schema
+  const schema = Schema.load(schemaId);
+
+  if (schema) {
+    if (!schema.attestationCounter) {
+      schema.attestationCounter = 1;
+    } else {
+      schema.attestationCounter += 1;
+    }
+
+    schema.save();
+  }
 }

subgraph/src/schema-registry.ts

@@ -14,6 +14,7 @@ export function handleSchemaCreated(event: SchemaCreatedEvent): void {
   schema.description = event.params.description;
   schema.context = event.params.context;
   schema.schema = event.params.schemaString;
+  schema.attestationCounter = 0;
 
   schema.save();
 }

subgraph/tests/attestation-registry.test.ts

@@ -129,6 +129,29 @@ describe("AttestationRegistry", () => {
       assert.fieldEquals("Portal", portal.toHexString(), "attestationCounter", "1");
     });
 
+    test("Should increment the attestations counter in schema", () => {
+      assert.entityCount("Attestation", 0);
+      assert.entityCount("Schema", 0);
+
+      const schemaEntity = new Schema(schemaId.toHexString());
+      schemaEntity.name = "name";
+      schemaEntity.description = "description";
+      schemaEntity.context = "context";
+      schemaEntity.schema = "schemaString";
+      schemaEntity.attestationCounter = 0;
+      schemaEntity.save();
+
+      assert.entityCount("Schema", 1);
+      assert.fieldEquals("Schema", schemaId.toHexString(), "attestationCounter", "0");
+
+      const attestationRegisteredEvent = createAttestationRegisteredEvent(attestationId);
+
+      handleAttestationRegistered(attestationRegisteredEvent);
+
+      assert.entityCount("Attestation", 1);
+      assert.fieldEquals("Schema", schemaId.toHexString(), "attestationCounter", "1");
+    });
+
     test("Should decode a basic attestation data", () => {
       const schema = new Schema(schemaId.toHexString());
       schema.name = "name";

subgraph/tests/schema-registry.test.ts

@@ -35,6 +35,7 @@ describe("handleSchemaCreated()", () => {
     assert.fieldEquals("Schema", schemaId, "description", schemaDescription);
     assert.fieldEquals("Schema", schemaId, "context", schemaContext);
     assert.fieldEquals("Schema", schemaId, "schema", schemaString);
+    assert.fieldEquals("Schema", schemaId, "attestationCounter", "0");
   });
 
   test("Should increment the schemas Counter", () => {