feat(jslib): add `getAs` convenience function to UpObject

sdks/js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@upnd/upend",
-  "version": "0.5.5",
+  "version": "0.6.0",
   "description": "Client library to interact with the UpEnd system.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

sdks/js/src/index.ts

@@ -98,6 +98,34 @@ export class UpObject {
     return this.attr[attr]?.[0].value.c;
   }
 
+  public getAs(attribute: string, as: "string"): string | undefined;
+  public getAs(attribute: string, as: "number"): number | undefined;
+  public getAs(attribute: string, as: "null"): null | undefined;
+  public getAs(
+    attribute: string,
+    as: "string" | "number" | "null",
+  ): string | number | null | undefined {
+    const value = this.attr[attribute]?.[0].value;
+    if (as === undefined) {
+      return this.attr[attribute]?.[0].value.c;
+    } else if (as === "string") {
+      return value?.c?.toString();
+    } else if (as === "number") {
+      switch (value?.t) {
+        case "Number":
+          return value.c;
+        case "String": {
+          const converted = parseFloat(value.c);
+          return isNaN(converted) ? undefined : converted;
+        }
+        default:
+          return undefined;
+      }
+    } else if (as === "null") {
+      return value?.t === "Null" ? null : undefined;
+    }
+  }
+
   public identify(): string[] {
     return (this.attr["LBL"] || []).map((e) => String(e.value.c));
   }

sdks/js/tests/upobject.test.ts

@@ -0,0 +1,65 @@
+import { UpListing, UpObject } from "../";
+
+function testObj() {
+  const listing = new UpListing({
+    a: {
+      entity: "test",
+      attribute: "string",
+      value: { t: "String", c: "hello" },
+      provenance: "test",
+      timestamp: "0",
+      user: "test",
+    },
+    b: {
+      entity: "test",
+      attribute: "number",
+      value: { t: "Number", c: 1 },
+      provenance: "test",
+      timestamp: "0",
+      user: "test",
+    },
+    c: {
+      entity: "test",
+      attribute: "null",
+      value: { t: "Null", c: null },
+      provenance: "test",
+      timestamp: "0",
+      user: "test",
+    },
+    d: {
+      entity: "test",
+      attribute: "stringy_number",
+      value: { t: "String", c: "3" },
+      provenance: "test",
+      timestamp: "0",
+      user: "test",
+    },
+  });
+  return new UpObject("test", listing);
+}
+
+describe("UpObject get function", () => {
+  test("getting as string works", () => {
+    const obj = testObj();
+    expect(obj.getAs("string", "string")).toBe("hello");
+    expect(obj.getAs("number", "string")).toBe("1");
+    expect(obj.getAs("null", "string")).toBe(undefined);
+    expect(obj.getAs("stringy_number", "string")).toBe("3");
+  });
+
+  test("getting as number works", () => {
+    const obj = testObj();
+    expect(obj.getAs("string", "number")).toBe(undefined);
+    expect(obj.getAs("number", "number")).toBe(1);
+    expect(obj.getAs("null", "number")).toBe(undefined);
+    expect(obj.getAs("stringy_number", "number")).toBe(3);
+  });
+
+  test("getting as null works", () => {
+    const obj = testObj();
+    expect(obj.getAs("string", "null")).toBe(undefined);
+    expect(obj.getAs("number", "null")).toBe(undefined);
+    expect(obj.getAs("null", "null")).toBe(null);
+    expect(obj.getAs("stringy_number", "null")).toBe(undefined);
+  });
+});