From 9c1986db6532f0a5de4d57224bc388a247a1ab71 Mon Sep 17 00:00:00 2001
From: Sky <sky@sky9.dev>
Date: Sat, 6 Jan 2024 15:30:18 -0500
Subject: [PATCH] [crates] MSRV Badge

Crates.io MSRV: `/crates/msrv/:crate`
Crates.io MSRV (version): `/crates/msrv/:crate/:version`
---
 services/crates/crates-base.js         |  2 +
 services/crates/crates-msrv.service.js | 74 ++++++++++++++++++++++++++
 services/crates/crates-msrv.tester.js  | 15 ++++++
 3 files changed, 91 insertions(+)
 create mode 100644 services/crates/crates-msrv.service.js
 create mode 100644 services/crates/crates-msrv.tester.js

diff --git a/services/crates/crates-base.js b/services/crates/crates-base.js
index aa4b7d378d911..86746405d9753 100644
--- a/services/crates/crates-base.js
+++ b/services/crates/crates-base.js
@@ -13,6 +13,7 @@ const crateSchema = Joi.object({
       Joi.object({
         downloads: nonNegativeInteger,
         license: Joi.string().required().allow(null),
+        rust_version: Joi.string().allow(null),
       }),
     )
     .min(1)
@@ -24,6 +25,7 @@ const versionSchema = Joi.object({
     downloads: nonNegativeInteger,
     num: Joi.string().required(),
     license: Joi.string().required().allow(null),
+    rust_version: Joi.string().allow(null),
   }).required(),
 }).required()
 
diff --git a/services/crates/crates-msrv.service.js b/services/crates/crates-msrv.service.js
new file mode 100644
index 0000000000000..b66b3477e952c
--- /dev/null
+++ b/services/crates/crates-msrv.service.js
@@ -0,0 +1,74 @@
+import { NotFound, pathParams } from '../index.js'
+import {
+  BaseCratesService,
+  description as cratesIoDescription,
+} from './crates-base.js'
+
+const description = `
+${cratesIoDescription}
+
+MSRV is a crate's minimum suppported rust version,
+the oldest version of Rust supported by the crate.
+See the [Cargo Book](https://doc.rust-lang.org/cargo/reference/manifest.html#the-rust-version-field)
+for more info.
+`
+
+export default class CratesMSRV extends BaseCratesService {
+  static category = 'platform-support'
+  static route = {
+    base: 'crates/msrv',
+    pattern: ':crate/:version?',
+  }
+
+  static openApi = {
+    '/crates/msrv/{crate}': {
+      get: {
+        summary: 'Crates.io MSRV',
+        description,
+        parameters: pathParams({
+          name: 'crate',
+          example: 'serde',
+        }),
+      },
+    },
+    '/crates/msrv/{crate}/{version}': {
+      get: {
+        summary: 'Crates.io MSRV (version)',
+        description,
+        parameters: pathParams(
+          {
+            name: 'crate',
+            example: 'serde',
+          },
+          {
+            name: 'version',
+            example: '1.0.194',
+          },
+        ),
+      },
+    },
+  }
+
+  static defaultBadgeData = { label: 'msrv', color: 'blue' }
+
+  static transform({ errors, version, versions }) {
+    // crates.io returns a 200 response with an errors object in
+    // error scenarios, e.g. https://crates.io/api/v1/crates/libc/0.1
+    if (errors) {
+      throw new NotFound({ prettyMessage: errors[0].detail })
+    }
+
+    const msrv = version ? version.rust_version : versions[0].rust_version
+    if (!msrv) {
+      throw new NotFound({ prettyMessage: 'unknown' })
+    }
+
+    return { msrv }
+  }
+
+  async handle({ crate, version }) {
+    const json = await this.fetch({ crate, version })
+    const { msrv } = this.constructor.transform(json)
+    return { message: msrv }
+  }
+}
diff --git a/services/crates/crates-msrv.tester.js b/services/crates/crates-msrv.tester.js
new file mode 100644
index 0000000000000..bc2ae6e35c33a
--- /dev/null
+++ b/services/crates/crates-msrv.tester.js
@@ -0,0 +1,15 @@
+import { createServiceTester } from '../tester.js'
+export const t = await createServiceTester()
+
+// dummy crate i created specifically for this test case
+t.create('msrv')
+  .get('/shields-test-dummy-crate-msrv-3452398210.json')
+  .expectBadge({ label: 'msrv', message: '1.69' })
+
+t.create('msrv (with version)')
+  .get('/shields-test-dummy-crate-msrv-3452398210/0.69.0.json')
+  .expectBadge({ label: 'msrv', message: '1.69' })
+
+t.create('msrv (not found)')
+  .get('/not-a-real-package.json')
+  .expectBadge({ label: 'msrv', message: 'not found' })