Feature: io.random() (#716)

* Add io.random

* Add changeset

---------

Co-authored-by: Eric Allam <eric@trigger.dev>

Author: nicktrn

.changeset/good-dolphins-jam.md

@@ -0,0 +1,5 @@
+---
+"@trigger.dev/sdk": patch
+---
+
+Add `io.random()` which wraps `Math.random()` in a Task with helpful options.

docs/_snippets/random-example.mdx

@@ -0,0 +1,21 @@
+```typescript Random example
+client.defineJob({
+  id: "random-job",
+  name: "Random Job",
+  version: "0.0.1",
+  trigger: eventTrigger({
+    name: "example.event",
+  }),
+  run: async (payload, io, ctx) => {
+    // generate random numbers
+    const small = await io.random("random-small");    
+    const large = await io.random("random-large", {
+      min: 10,
+      max: 200,
+      round: true
+    });
+
+    await io.logger.info(`${small} is smaller than ${large}`);
+  },
+});
+```

docs/mint.json

@@ -335,6 +335,7 @@
             "sdk/io/logger",
             "sdk/io/sendevent",
             "sdk/io/backgroundfetch",
+            "sdk/io/random",
             "sdk/io/try",
             "sdk/io/registerinterval",
             "sdk/io/unregisterinterval",

docs/sdk/io/overview.mdx

@@ -40,6 +40,10 @@ If you want to send an event from outside a run (e.g. just from your backend) yo
 
 `io.backgroundFetch()` allows you to fetch data from a URL that can take longer that the serverless timeout. The actual `fetch` request is performed on the Trigger.dev platform, and the response is sent back to you. An example use case is fetching data from a slow API, like some AI endpoints.
 
+### [random()](/sdk/io/random)
+
+`io.random()` is identical to `Math.random()` when called without options but ensures your random numbers are not regenerated on resume or retry. It will return a pseudo-random floating-point number between optional `min` (default: 0, inclusive) and `max` (default: 1, exclusive). Can optionally `round` to the nearest integer.
+
 ### [try()](/sdk/io/try)
 
 `io.try()` allows you to run Tasks and catch any errors that are thrown, it's similar to a normal `try/catch` block but works with [io.runTask()](/sdk/io/runtask).

docs/sdk/io/random.mdx

@@ -0,0 +1,26 @@
+---
+title: "io.random()"
+sidebarTitle: "random()"
+description: "`io.random()` is identical to `Math.random()` when called without options but ensures your random numbers are not regenerated on resume or retry. It will return a pseudo-random floating-point number between optional `min` (default: 0, inclusive) and `max` (default: 1, exclusive). Can optionally `round` to the nearest integer."
+---
+
+## Parameters
+
+<Snippet file="stable-key-param.mdx" />
+<ResponseField name="min" type="number" default="0" required>
+  Sets the lower bound (inclusive). Can't be higher than `max`.
+</ResponseField>
+<ResponseField name="max" type="number" default="1" required>
+  Sets the upper bound (exclusive). Can't be lower than `min`.
+</ResponseField>
+<ResponseField name="round" type="boolean" default="false" required>
+  Controls rounding to the nearest integer. Any `max` integer will become inclusive when enabled. Rounding with floating-point bounds may cause unexpected skew and boundary inclusivity.
+</ResponseField>
+
+## Returns
+
+A `Promise` that resolves with a pseudo-random number. Always resolves to an integer when rounding is enabled.
+
+<RequestExample>
+  <Snippet file="random-example.mdx" />
+</RequestExample>

packages/trigger-sdk/src/io.ts

@@ -232,6 +232,90 @@ export class IO {
     });
   }
 
+  /** `io.random()` is identical to `Math.random()` when called without options but ensures your random numbers are not regenerated on resume or retry. It will return a pseudo-random floating-point number between optional `min` (default: 0, inclusive) and `max` (default: 1, exclusive). Can optionally `round` to the nearest integer.
+   * @param cacheKey Should be a stable and unique key inside the `run()`. See [resumability](https://trigger.dev/docs/documentation/concepts/resumability) for more information.
+   * @param min Sets the lower bound (inclusive). Can't be higher than `max`.
+   * @param max Sets the upper bound (exclusive). Can't be lower than `min`.
+   * @param round Controls rounding to the nearest integer. Any `max` integer will become inclusive when enabled. Rounding with floating-point bounds may cause unexpected skew and boundary inclusivity.
+   */
+  async random(
+    cacheKey: string | any[],
+    {
+      min = 0,
+      max = 1,
+      round = false,
+    }: {
+      min?: number;
+      max?: number;
+      round?: boolean;
+    } = {}
+  ) {
+    return await this.runTask(
+      cacheKey,
+      async (task) => {
+        if (min > max) {
+          throw new Error(
+            `Lower bound can't be higher than upper bound - min: ${min}, max: ${max}`
+          );
+        }
+
+        if (min === max) {
+          await this.logger.warn(
+            `Lower and upper bounds are identical. The return value is not random and will always be: ${min}`
+          );
+        }
+
+        const withinBounds = (max - min) * Math.random() + min;
+
+        if (!round) {
+          return withinBounds;
+        }
+
+        if (!Number.isInteger(min) || !Number.isInteger(max)) {
+          await this.logger.warn(
+            "Rounding enabled with floating-point bounds. This may cause unexpected skew and boundary inclusivity."
+          );
+        }
+
+        const rounded = Math.round(withinBounds);
+
+        return rounded;
+      },
+      {
+        name: "random",
+        icon: "dice-5-filled",
+        params: { min, max, round },
+        properties: [
+          ...(min === 0
+            ? []
+            : [
+                {
+                  label: "min",
+                  text: String(min),
+                },
+              ]),
+          ...(max === 1
+            ? []
+            : [
+                {
+                  label: "max",
+                  text: String(max),
+                },
+              ]),
+          ...(round === false
+            ? []
+            : [
+                {
+                  label: "round",
+                  text: String(round),
+                },
+              ]),
+        ],
+        style: { style: "minimal" },
+      }
+    );
+  }
+
   /** `io.wait()` waits for the specified amount of time before continuing the Job. Delays work even if you're on a serverless platform with timeouts, or if your server goes down. They utilize [resumability](https://trigger.dev/docs/documentation/concepts/resumability) to ensure that the Run can be resumed after the delay.
    * @param cacheKey Should be a stable and unique key inside the `run()`. See [resumability](https://trigger.dev/docs/documentation/concepts/resumability) for more information.
    * @param seconds The number of seconds to wait. This can be very long, serverless timeouts are not an issue.
@@ -975,7 +1059,7 @@ export class IO {
    */
   brb = this.yield.bind(this);
 
-  /** `io.try()` allows you to run Tasks and catch any errors that are thrown, it's similar to a normal `try/catch` block but works with [io.runTask()](/sdk/io/runtask).
+  /** `io.try()` allows you to run Tasks and catch any errors that are thrown, it's similar to a normal `try/catch` block but works with [io.runTask()](https://trigger.dev/docs/sdk/io/runtask).
    * A regular `try/catch` block on its own won't work as expected with Tasks. Internally `runTask()` throws some special errors to control flow execution. This is necessary to deal with resumability, serverless timeouts, and retrying Tasks.
    * @param tryCallback The code you wish to run
    * @param catchCallback Thhis will be called if the Task fails. The callback receives the error

references/job-catalog/package.json

@@ -29,6 +29,7 @@
     "misconfigured": "nodemon --watch src/misconfigured.ts -r tsconfig-paths/register -r dotenv/config src/misconfigured.ts",
     "auto-yield": "nodemon --watch src/auto-yield.ts -r tsconfig-paths/register -r dotenv/config src/auto-yield.ts",
     "cli-example": "nodemon --watch src/cli-example.ts -r tsconfig-paths/register -r dotenv/config src/cli-example.ts",
+    "random": "nodemon --watch src/random.ts -r tsconfig-paths/register -r dotenv/config src/random.ts",
     "invoke": "nodemon --watch src/invoke.ts -r tsconfig-paths/register -r dotenv/config src/invoke.ts",
     "dev:trigger": "trigger-cli dev --port 8080"
   },

references/job-catalog/src/random.ts

@@ -0,0 +1,51 @@
+import { createExpressServer } from "@trigger.dev/express";
+import { TriggerClient, eventTrigger } from "@trigger.dev/sdk";
+
+export const client = new TriggerClient({
+  id: "job-catalog",
+  apiKey: process.env["TRIGGER_API_KEY"],
+  apiUrl: process.env["TRIGGER_API_URL"],
+  verbose: false,
+  ioLogLocalEnabled: true,
+});
+
+client.defineJob({
+  id: "random-example",
+  name: "Random Example",
+  version: "1.0.0",
+  enabled: true,
+  trigger: eventTrigger({
+    name: "random.example",
+  }),
+  run: async (payload, io, ctx) => {
+    // just like Math.random() but wrapped in a Task
+    await io.random("random-native");
+
+    // set lower and upper bounds - defaults to 0, 1 respectively
+    await io.random("random-min-max", { min: 10, max: 20 });
+
+    // set lower bound only (inclusive)
+    await io.random("random-min", { min: 0.5 });
+
+    // set upper bound only (exclusive)
+    await io.random("random-max", { max: 100 });
+
+    // round to the nearest integer
+    await io.random("random-round", { min: 100, max: 1000, round: true });
+
+    // rounding with floating-point bounds results in a warning
+    // this example will unexpectedly (but correctly!) output 1 or 2, skewing towards 2
+    await io.random("random-round-float", { min: 0.9, max: 2.5, round: true });
+
+    // negative values work just fine
+    await io.random("random-negative", { min: -100, max: -50 });
+
+    // identical lower and upper bounds result in a warning
+    await io.random("random-warn-bounds", { min: 10, max: 10 });
+
+    // invalid ranges will fail
+    await io.random("random-error", { min: 10, max: 5 });
+  },
+});
+
+createExpressServer(client);