refactor: several improvements (#262)

- more tests
- file read in config
- reduce if depth
- reduce unnecessary requests

src/config.ts

@@ -1,13 +1,12 @@
 import * as core from '@actions/core'
 import {context} from '@actions/github'
+import {readFileSync} from 'fs'
 
 export const pullRequestNumber =
   context?.payload?.pull_request?.number ||
   +core.getInput('number', {required: false})
 
 export const repo = buildRepo()
-export const message = core.getInput('message', {required: false})
-export const path = core.getInput('path', {required: false})
 export const header = core.getInput('header', {required: false})
 export const append = core.getInput('append', {required: true}) === 'true'
 export const recreate = core.getInput('recreate', {required: true}) === 'true'
@@ -15,9 +14,25 @@ export const deleteOldComment =
   core.getInput('delete', {required: true}) === 'true'
 export const githubToken = core.getInput('GITHUB_TOKEN', {required: true})
 
+export const body = buildBody()
+
 function buildRepo(): {repo: string; owner: string} {
   return {
     owner: context.repo.owner,
     repo: core.getInput('repo', {required: false}) || context.repo.repo
   }
 }
+
+function buildBody(): string {
+  const path = core.getInput('path', {required: false})
+  if (path) {
+    try {
+      return readFileSync(path, 'utf-8')
+    } catch (error) {
+      core.setFailed(error.message)
+      return ''
+    }
+  } else {
+    return core.getInput('message', {required: false})
+  }
+}

src/main.ts

@@ -9,15 +9,13 @@ import {
 import {
   pullRequestNumber,
   repo,
-  message,
-  path,
+  body,
   header,
   append,
   recreate,
   deleteOldComment,
   githubToken
 } from './config'
-import {readFileSync} from 'fs'
 
 async function run(): Promise<undefined> {
   if (isNaN(pullRequestNumber) || pullRequestNumber < 1) {
@@ -26,6 +24,14 @@ async function run(): Promise<undefined> {
   }
 
   try {
+    if (!deleteOldComment && !body) {
+      throw new Error('Either message or path input is required')
+    }
+
+    if (deleteOldComment && recreate) {
+      throw new Error('delete and recreate cannot be both set to true')
+    }
+
     const octokit = github.getOctokit(githubToken)
     const previous = await findPreviousComment(
       octokit,
@@ -34,49 +40,31 @@ async function run(): Promise<undefined> {
       header
     )
 
-    if (!deleteOldComment && !message && !path) {
-      throw new Error('Either message or path input is required')
-    }
-
-    if (deleteOldComment && recreate) {
-      throw new Error('delete and recreate cannot be both set to true')
-    }
-
-    let body
-
-    if (path) {
-      body = readFileSync(path, 'utf-8')
-    } else {
-      body = message
-    }
-
-    if (previous) {
-      const previousBody = append ? previous.body : undefined
-      if (deleteOldComment) {
-        await deleteComment(octokit, repo, previous.id)
-      } else if (recreate) {
-        await deleteComment(octokit, repo, previous.id)
-        await createComment(
-          octokit,
-          repo,
-          pullRequestNumber,
-          body,
-          header,
-          previousBody
-        )
-      } else {
-        await updateComment(
-          octokit,
-          repo,
-          previous.id,
-          body,
-          header,
-          previousBody
-        )
-      }
-    } else {
+    if (!previous) {
       await createComment(octokit, repo, pullRequestNumber, body, header)
+      return
     }
+
+    if (deleteOldComment) {
+      await deleteComment(octokit, repo, previous.id)
+      return
+    }
+
+    const previousBody = append ? previous.body : undefined
+    if (recreate) {
+      await deleteComment(octokit, repo, previous.id)
+      await createComment(
+        octokit,
+        repo,
+        pullRequestNumber,
+        body,
+        header,
+        previousBody
+      )
+      return
+    }
+
+    await updateComment(octokit, repo, previous.id, body, header, previousBody)
   } catch (error) {
     core.setFailed(error.message)
   }