From 4165c6cab42affee7f40f5493e29e06a90c67ec4 Mon Sep 17 00:00:00 2001
From: Sam Rose <hello@samwho.dev>
Date: Tue, 1 Oct 2024 16:06:40 +0100
Subject: [PATCH] Test all aggregation types.

---
 .../src/api/routes/tests/viewV2.spec.ts       | 55 +++++++++++++++++++
 packages/server/src/integrations/postgres.ts  |  3 +-
 .../src/utilities/rowProcessor/index.ts       | 19 +++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/packages/server/src/api/routes/tests/viewV2.spec.ts b/packages/server/src/api/routes/tests/viewV2.spec.ts
index b03c445b78..1d6c1d50cd 100644
--- a/packages/server/src/api/routes/tests/viewV2.spec.ts
+++ b/packages/server/src/api/routes/tests/viewV2.spec.ts
@@ -2490,6 +2490,61 @@ describe.each([
               expect(row["Total Price"]).toEqual(priceByQuantity[row.quantity])
             }
           })
+
+          it.each([
+            CalculationType.COUNT,
+            CalculationType.SUM,
+            CalculationType.AVG,
+            CalculationType.MIN,
+            CalculationType.MAX,
+          ])("should be able to calculate $type", async type => {
+            const view = await config.api.viewV2.create({
+              tableId: table._id!,
+              name: generator.guid(),
+              schema: {
+                aggregate: {
+                  visible: true,
+                  calculationType: type,
+                  field: "price",
+                },
+              },
+            })
+
+            const response = await config.api.viewV2.search(view.id, {
+              query: {},
+            })
+
+            function calculate(
+              type: CalculationType,
+              numbers: number[]
+            ): number {
+              switch (type) {
+                case CalculationType.COUNT:
+                  return numbers.length
+                case CalculationType.SUM:
+                  return numbers.reduce((a, b) => a + b, 0)
+                case CalculationType.AVG:
+                  return numbers.reduce((a, b) => a + b, 0) / numbers.length
+                case CalculationType.MIN:
+                  return Math.min(...numbers)
+                case CalculationType.MAX:
+                  return Math.max(...numbers)
+              }
+            }
+
+            const prices = rows.map(row => row.price)
+            const expected = calculate(type, prices)
+            const actual = response.rows[0].aggregate
+
+            if (type === CalculationType.AVG) {
+              // The average calculation can introduce floating point rounding
+              // errors, so we need to compare to within a small margin of
+              // error.
+              expect(actual).toBeCloseTo(expected)
+            } else {
+              expect(actual).toEqual(expected)
+            }
+          })
         })
     })
 
diff --git a/packages/server/src/integrations/postgres.ts b/packages/server/src/integrations/postgres.ts
index 3652864991..ce8b21eede 100644
--- a/packages/server/src/integrations/postgres.ts
+++ b/packages/server/src/integrations/postgres.ts
@@ -272,7 +272,8 @@ class PostgresIntegration extends Sql implements DatasourcePlus {
     try {
       const bindings = query.bindings || []
       this.log(query.sql, bindings)
-      return await client.query(query.sql, bindings)
+      const result = await client.query(query.sql, bindings)
+      return result
     } catch (err: any) {
       await this.closeConnection()
       let readableMessage = getReadableErrorMessage(
diff --git a/packages/server/src/utilities/rowProcessor/index.ts b/packages/server/src/utilities/rowProcessor/index.ts
index bddd590f25..7332f8b244 100644
--- a/packages/server/src/utilities/rowProcessor/index.ts
+++ b/packages/server/src/utilities/rowProcessor/index.ts
@@ -426,6 +426,25 @@ export async function coreOutputProcessing(
         }
       }
     }
+
+    if (sdk.views.isView(source)) {
+      const calculationFields = Object.keys(
+        helpers.views.calculationFields(source)
+      )
+
+      // We ensure all calculation fields are returned as numbers.  During the
+      // testing of this feature it was discovered that the COUNT operation
+      // returns a string for MySQL, MariaDB, and Postgres. But given that all
+      // calculation fields should be numbers, we blanket make sure of that
+      // here.
+      for (const key of calculationFields) {
+        for (const row of rows) {
+          if (typeof row[key] === "string") {
+            row[key] = parseFloat(row[key])
+          }
+        }
+      }
+    }
   }
 
   if (!isUserMetadataTable(table._id!)) {