Format errors better, add a test

Author: JasonEtco

src/action.ts

@@ -4,9 +4,10 @@ import fm from 'front-matter'
 import nunjucks from 'nunjucks'
 // @ts-ignore
 import dateFilter from 'nunjucks-date-filter'
+import { ZodError } from 'zod'
 import { FrontMatterAttributes, frontmatterSchema, listToArray, setOutputs } from './helpers'
 
-function logError(tools: Toolkit, template: string, action: 'creating' | 'updating', err: any) {
+function logError(tools: Toolkit, template: string, action: 'creating' | 'updating' | 'parsing', err: any) {
   // Log the error message
   const errorMessage = `An error occurred while ${action} the issue. This might be caused by a malformed issue title, or a typo in the labels or assignees. Check ${template}!`
   tools.log.error(errorMessage)
@@ -51,7 +52,18 @@ export async function createAnIssue (tools: Toolkit) {
 
   // Grab the front matter as JSON
   const { attributes: rawAttributes, body } = fm<FrontMatterAttributes>(file)
-  const attributes = await frontmatterSchema.parseAsync(rawAttributes)
+
+  let attributes: FrontMatterAttributes
+  try {
+    attributes = await frontmatterSchema.parseAsync(rawAttributes)
+  } catch (err) {
+    if (err instanceof ZodError) {
+      const formatted = err.format()
+      return logError(tools, template, 'parsing', formatted)
+    }
+    throw err
+  }
+
   tools.log(`Front matter for ${template} is`, attributes)
 
   const templated = {

src/helpers.ts

@@ -6,7 +6,7 @@ export const frontmatterSchema = z.object({
   assignees: z.union([z.array(z.string()), z.string()]).optional(),
   labels: z.union([z.array(z.string()), z.string()]).optional(),
   milestone: z.union([z.string(), z.number()]).optional()
-})
+}).strict()
 
 export type FrontMatterAttributes = z.infer<typeof frontmatterSchema>
 

tests/__snapshots__/index.test.ts.snap

@@ -232,6 +232,32 @@ exports[`create-an-issue logs a helpful error if creating an issue throws an err
 ]
 `;
 
+exports[`create-an-issue logs a helpful error if the frontmatter is invalid 1`] = `
+[
+  [
+    "An error occurred while parsing the issue. This might be caused by a malformed issue title, or a typo in the labels or assignees. Check .github/invalid-frontmatter.md!",
+  ],
+  [
+    {
+      "_errors": [
+        "Unrecognized key(s) in object: 'name', 'not_a_thing'",
+      ],
+      "labels": {
+        "_errors": [
+          "Expected array, received number",
+          "Expected string, received number",
+        ],
+      },
+      "title": {
+        "_errors": [
+          "Required",
+        ],
+      },
+    },
+  ],
+]
+`;
+
 exports[`create-an-issue logs a helpful error if updating an issue throws an error with more errors 1`] = `
 [
   [

tests/fixtures/.github/invalid-frontmatter.md

@@ -0,0 +1,6 @@
+---
+name: "Not a title"
+labels: 123
+not_a_thing: "testing"
+---
+Hi!

tests/index.test.ts

@@ -302,4 +302,13 @@ describe('create-an-issue', () => {
     expect((tools.log.error as any).mock.calls).toMatchSnapshot()
     expect(tools.exit.failure).toHaveBeenCalled()
   })
+
+  it('logs a helpful error if the frontmatter is invalid', async () => {
+    process.env.INPUT_FILENAME = '.github/invalid-frontmatter.md'
+
+    await createAnIssue(tools)
+    expect(tools.log.error).toHaveBeenCalled()
+    expect((tools.log.error as any).mock.calls).toMatchSnapshot()
+    expect(tools.exit.failure).toHaveBeenCalled()
+  })
 })