feat: add ability to introspect query

VeryBigThings · Mar 20, 2024 · 65b023f · 65b023f
1 parent f436c73
commit 65b023f
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Showing 2 changed files with 87 additions and 2 deletions.
diff --git a/src/__tests__/index.test.ts b/src/__tests__/index.test.ts
@@ -6,12 +6,12 @@ import {
   PostgreSqlContainer,
   StartedPostgreSqlContainer,
 } from "@testcontainers/postgresql";
+import { InferSqlQueryResultType, QueryBuilderQuery } from "../index.js";
 
 import fs from "node:fs/promises";
 import path from "node:path";
 import pg from "pg";
 import { zodToJsonSchema } from "zod-to-json-schema";
-import { InferSqlQueryResultType } from "../index.js";
 
 //import { format as sqlFormat } from "sql-formatter";
 
@@ -1083,7 +1083,7 @@ await describe("semantic layer", async () => {
     });
   });
 
-  await describe("model descriptions", async () => {
+  await describe("model descriptions and query introspection", async () => {
     const customersModel = C.model("customers")
       .fromSqlQuery('select * from "Customer"')
       .withDimension("customer_id", {
@@ -1123,6 +1123,8 @@ await describe("semantic layer", async () => {
           sql`${dimensions.customers.customer_id} = ${dimensions.invoices.customer_id}`,
       );
 
+    const queryBuilder = repository.build("postgresql");
+
     await it("allows access to the model descriptions", () => {
       const docs: string[] = [];
       const dimensions = repository.getDimensions();
@@ -1149,5 +1151,49 @@ await describe("semantic layer", async () => {
         "METRIC: invoices.total, TYPE: string, DESCRIPTION: -, FORMAT: percentage",
       ]);
     });
+
+    await it("allows introspection of a query", () => {
+      const query: QueryBuilderQuery<typeof queryBuilder> = {
+        dimensions: [
+          "customers.customer_id",
+          "invoices.invoice_id",
+          "invoices.customer_id",
+        ],
+        metrics: ["invoices.total"],
+      };
+
+      const introspection = queryBuilder.introspect(query);
+
+      assert.deepEqual(introspection, {
+        customers___customer_id: {
+          memberType: "dimension",
+          path: "customers.customer_id",
+          type: "number",
+          description: "The unique identifier of the customer",
+          format: undefined,
+        },
+        invoices___invoice_id: {
+          memberType: "dimension",
+          path: "invoices.invoice_id",
+          type: "number",
+          description: "The unique identifier of the invoice",
+          format: undefined,
+        },
+        invoices___customer_id: {
+          memberType: "dimension",
+          path: "invoices.customer_id",
+          type: "number",
+          description: "The unique identifier of the invoice customer",
+          format: undefined,
+        },
+        invoices___total: {
+          memberType: "metric",
+          path: "invoices.total",
+          format: "percentage",
+          type: "string",
+          description: undefined,
+        },
+      });
+    });
   });
 });
diff --git a/src/lib/query-builder.ts b/src/lib/query-builder.ts
@@ -1,7 +1,9 @@
 import {
   AnyQuery,
   AnyQueryFilter,
+  MemberFormat,
   MemberNameToType,
+  MemberType,
   Query,
   QueryMemberName,
   QueryReturnType,
@@ -148,4 +150,41 @@ export class QueryBuilder<
 
     return result;
   }
+
+  introspect(query: AnyQuery) {
+    const queryDimensions = query.dimensions ?? [];
+    const queryMetrics = query.metrics ?? [];
+
+    return [...queryDimensions, ...queryMetrics].reduce<
+      Record<
+        string,
+        {
+          memberType: "dimension" | "metric";
+          path: string;
+          format?: MemberFormat;
+          type: MemberType;
+          description?: string;
+        }
+      >
+    >((acc, memberName) => {
+      const member = this.repository.getMember(memberName);
+      acc[memberName.replaceAll(".", "___")] = {
+        memberType: member.isDimension() ? "dimension" : "metric",
+        path: member.getPath(),
+        format: member.getFormat(),
+        type: member.getType(),
+        description: member.getDescription(),
+      };
+
+      return acc;
+    }, {});
+  }
 }
+
+export type QueryBuilderQuery<Q> = Q extends QueryBuilder<
+  infer D,
+  infer M,
+  infer F
+>
+  ? Query<string & keyof D, string & keyof M, F>
+  : never;