Handling writing empty arrays (#6)

Added a case where, if there are no data, it will write an empty array
(`[]`) to the file.

This is useful to handle the case of reading non existing files.

README.md

@@ -67,6 +67,7 @@ You can find all the inputs in [the action file](./action.yml) but let's walk th
   - **default**: false
 - `fileOutput`: String. File to which the output from `data` should be written. 
   - Useful in the cases where the output is too big and GitHub Actions can not handle it as a variable.
+  - Make sure that the directory exists, else it will fail
 
 #### Accessing other repositories
 

action.yml

@@ -37,4 +37,4 @@ outputs:
 
 runs:
   using: 'docker'
-  image: 'docker://ghcr.io/paritytech/stale-pr-finder/action:0.0.2'
+  image: 'docker://ghcr.io/paritytech/stale-pr-finder/action:0.0.3'

package.json

@@ -1,6 +1,6 @@
 {
   "name": "stale-pr-finder",
-  "version": "0.0.2",
+  "version": "0.0.3",
   "description": "GitHub action that finds stale PRs and produce an output with them",
   "main": "src/index.ts",
   "scripts": {

src/index.ts

@@ -1,4 +1,4 @@
-import { debug, getBooleanInput, getInput, info, setFailed, setOutput, summary } from "@actions/core";
+import { debug, getBooleanInput, getInput, info, setOutput, summary } from "@actions/core";
 import { context } from "@actions/github";
 import { Context } from "@actions/github/lib/context";
 import { github } from "@eng-automation/integrations";
@@ -14,6 +14,18 @@ const daysSinceDate = (date: string): number => {
     return moment().diff(moment(date), 'days')
 }
 
+const writeToFile = async (fileName: string, content: string) => {
+    return new Promise<void>((res, rej) => {
+        writeFile(fileName, content, err => {
+            if (err) {
+                rej(err)
+            } else {
+                res();
+            }
+        })
+    })
+}
+
 const getFiltersFromInput = (): Filters => {
     const inputDays = Number.parseInt(getInput("days-stale", { required: false }));
     const daysStale = isNaN(inputDays) ? 5 : inputDays;
@@ -106,11 +118,7 @@ const runAction = async (ctx: Context) => {
         setOutput("message", message);
 
         if (outputFile) {
-            writeFile(outputFile, jsonData, err => {
-                if (err) {
-                    setFailed(err);
-                }
-            })
+            await writeToFile(outputFile, jsonData);
         }
 
         await summary.addHeading(`${repo.owner}/${repo.repo}`)
@@ -123,6 +131,9 @@ const runAction = async (ctx: Context) => {
     } else {
         setOutput("message", `### Repo ${repo.owner}/${repo.repo} has no stale Pull Requests`);
         info(`Repo ${repo.owner}/${repo.repo} has no stale Pull Requests`);
+        if (outputFile) {
+            await writeToFile(outputFile, "[]");
+        }
     }
 }