Add and configure ESLint and update configuration for Prettier (#26)

* Add ESLint and Prettier

* Rebuild action

* Update package.json

* Update licenses

* Fix review points

src/api-utils.ts

@@ -1,114 +1,115 @@
 import * as core from '@actions/core';
-import { context } from '@actions/github';
-import { GitHub } from '@actions/github/lib/utils';
-import { HttpClient } from '@actions/http-client';
+import {context} from '@actions/github';
+import {GitHub} from '@actions/github/lib/utils';
+import {HttpClient} from '@actions/http-client';
 
 interface GitRef {
-    ref: string;
-    node_id: string;
+  ref: string;
+  node_id: string;
+  url: string;
+  object: {
+    type: string;
+    sha: string;
     url: string;
-    object: {
-        type: string;
-        sha: string;
-        url: string;
-    };
+  };
 }
 
 async function findTag(
-    tag: string,
-    octokitClient: InstanceType<typeof GitHub>
+  tag: string,
+  octokitClient: InstanceType<typeof GitHub>
 ): Promise<GitRef | null> {
-    try {
-        const { data: foundTag } = await octokitClient.git.getRef({
-            ...context.repo,
-            ref: `tags/${tag}`
-        });
-        
-        return foundTag;
-    } catch (err) {
-        if (err.status === 404) {
-            return null;
-        } else {
-            throw new Error(
-                `Retrieving refs failed with the following error: ${err}`
-            );
-        }
+  try {
+    const {data: foundTag} = await octokitClient.git.getRef({
+      ...context.repo,
+      ref: `tags/${tag}`
+    });
+
+    return foundTag;
+  } catch (err) {
+    if (err.status === 404) {
+      return null;
+    } else {
+      throw new Error(
+        `Retrieving refs failed with the following error: ${err}`
+      );
     }
+  }
 }
 
 async function getTagSHA(
-    tag: string,
-    octokitClient: InstanceType<typeof GitHub>
+  tag: string,
+  octokitClient: InstanceType<typeof GitHub>
 ): Promise<string> {
-    const foundTag = await findTag(tag, octokitClient);
-    if (!foundTag) {
-        throw new Error(
-            `The '${tag}' tag does not exist in the remote repository`
-        );
-    }
+  const foundTag = await findTag(tag, octokitClient);
+  if (!foundTag) {
+    throw new Error(`The '${tag}' tag does not exist in the remote repository`);
+  }
 
-    return foundTag.object.sha;
+  return foundTag.object.sha;
 }
 
 export async function validateIfReleaseIsPublished(
-    tag: string,
-    octokitClient: InstanceType<typeof GitHub>
+  tag: string,
+  octokitClient: InstanceType<typeof GitHub>
 ): Promise<void> {
-    try {
-        const { data: foundRelease } = await octokitClient.repos.getReleaseByTag({
-            ...context.repo,
-            tag,
-        });
+  try {
+    const {data: foundRelease} = await octokitClient.repos.getReleaseByTag({
+      ...context.repo,
+      tag
+    });
 
-        if (foundRelease.prerelease) {
-            throw new Error(
-                `The '${foundRelease.name}' release is marked as pre-release. Updating tags for pre-release is not supported`
-            );
-        }
-    } catch (err) {
-        if (err.status === 404) {
-            throw new Error(
-                `No GitHub release found for the ${tag} tag`
-            );
-        } else {
-            throw new Error(
-                `Retrieving releases failed with the following error: ${err}`
-            );
-        }
+    if (foundRelease.prerelease) {
+      throw new Error(
+        `The '${foundRelease.name}' release is marked as pre-release. Updating tags for pre-release is not supported`
+      );
     }
+  } catch (err) {
+    if (err.status === 404) {
+      throw new Error(`No GitHub release found for the ${tag} tag`);
+    } else {
+      throw new Error(
+        `Retrieving releases failed with the following error: ${err}`
+      );
+    }
+  }
 }
 
 export async function updateTag(
-    sourceTag: string,
-    targetTag: string,
-    octokitClient: InstanceType<typeof GitHub>
+  sourceTag: string,
+  targetTag: string,
+  octokitClient: InstanceType<typeof GitHub>
 ): Promise<void> {
-    const sourceTagSHA = await getTagSHA(sourceTag, octokitClient);
-    const foundTargetTag = await findTag(targetTag, octokitClient);
-    const refName = `tags/${targetTag}`;
+  const sourceTagSHA = await getTagSHA(sourceTag, octokitClient);
+  const foundTargetTag = await findTag(targetTag, octokitClient);
+  const refName = `tags/${targetTag}`;
 
-    if (foundTargetTag) {
-        core.info(`Updating the '${targetTag}' tag to point to the '${sourceTag}' tag`);
+  if (foundTargetTag) {
+    core.info(
+      `Updating the '${targetTag}' tag to point to the '${sourceTag}' tag`
+    );
 
-        await octokitClient.git.updateRef({
-            ...context.repo,
-            ref: refName,
-            sha: sourceTagSHA,
-            force: true
-        });
-    } else {
-        core.info(`Creating the '${targetTag}' tag from the '${sourceTag}' tag`);
+    await octokitClient.git.updateRef({
+      ...context.repo,
+      ref: refName,
+      sha: sourceTagSHA,
+      force: true
+    });
+  } else {
+    core.info(`Creating the '${targetTag}' tag from the '${sourceTag}' tag`);
 
-        await octokitClient.git.createRef({
-            ...context.repo,
-            ref: `refs/${refName}`,
-            sha: sourceTagSHA
-        });
-    }
+    await octokitClient.git.createRef({
+      ...context.repo,
+      ref: `refs/${refName}`,
+      sha: sourceTagSHA
+    });
+  }
 }
 
-export async function postMessageToSlack(slackWebhook: string, message: string): Promise<void> {
-    const jsonData = {text: message}
-    const http = new HttpClient();
-    await http.postJson(slackWebhook, jsonData);
-}
+export async function postMessageToSlack(
+  slackWebhook: string,
+  message: string
+): Promise<void> {
+  const jsonData = {text: message};
+  const http = new HttpClient();
+  await http.postJson(slackWebhook, jsonData);
+}