refactor: several improvements (#262)

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

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)
   }