feat: add support for additional placeholders (#3)

Author: ToppleTheNun

.github/workflows/ci.yml

@@ -112,6 +112,9 @@ jobs:
         with:
           dryRun: true
           slackWebhook: "invalid-slack-webhook"
+          additionalPlaceholders: |
+            non-production=https://google.com
+          message: ":rocket: A new [[@linkify(it.links.commitSha, 'version') /]] of [[@linkify(it.links.repository, it.repository) /]] has been deployed to [[@linkify(it['non-production'], 'non-production') /]]!"
 
   release:
     name: 🚀 Release

README.md

@@ -44,3 +44,30 @@ We use [squirrelly](https://squirrelly.js.org/) as the templating engine with `[
 - `it.repository`: The shorthand name for the repo (e.g., `singlestone/commit-deploy-slack-action`)
 - `it.links.commitSha`: Link to the commit that triggered this action.
 - `it.links.repository`: Link to the repository that triggered this action.
+
+### Additional placeholders
+
+You can provide your own placeholders you can use with the message.
+
+```yaml
+name: Release
+
+on:
+  push:
+    branches:
+      - main
+
+concurrency: ${{ github.workflow }}-${{ github.ref }}
+
+jobs:
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Send a Slack notification
+        with:
+          additionalPlaceholders: |
+            non-production=https://google.com
+          message: ":rocket: A new [[@linkify(it.links.commitSha, 'version') /]] of [[@linkify(it.links.repository, it.repository) /]] has been deployed to [[@linkify(it['non-production'], 'non-production') /]]!"
+          slackWebhook: ${{ secrets.SLACK_WEBHOOK }}
+```

action.yml

@@ -17,6 +17,9 @@ inputs:
   slackWebhook:
     description: "Slack webhook to which notifications will be sent."
     required: true
+  additionalPlaceholders:
+    description: "Additional placeholders to make available for message use. Should be a multi-line string with keys separated from values by a =."
+    required: false
 runs:
   using: "node16"
   main: "dist/index.js"

src/index.test.ts

@@ -23,6 +23,7 @@ it("creates a templated Slack message", () => {
     JSON.parse(
       asSlackMessage(
         templateMessage({
+          additionalPlaceholders: {},
           configMessage:
             ":rocket: A new [[@linkify(it.links.commitSha, 'version') /]] of [[@linkify(it.links.repository, it.repository) /]] has been deployed!",
           github: fakeGitHubContext,

src/index.ts

@@ -3,6 +3,7 @@ import * as github from "@actions/github";
 
 import { asSlackMessage } from "./as-slack-message.js";
 import { notifySlackWebhook } from "./notify.js";
+import { reduceAdditionalPlaceholders } from "./reducers.js";
 import { register } from "./sqrl/register.js";
 import { templateMessage } from "./template-message.js";
 
@@ -13,8 +14,15 @@ import { templateMessage } from "./template-message.js";
   const webhook = core.getInput("slackWebhook", { required: true });
   const configMessage = core.getInput("message");
   const linkRoot = core.getInput("linkRoot") || "https://github.com";
+  const additionalPlaceholdersAsArray = core.getMultilineInput(
+    "additionalPlaceholders",
+  );
+  const additionalPlaceholders = reduceAdditionalPlaceholders(
+    additionalPlaceholdersAsArray,
+  );
 
   const templatedMessage = templateMessage({
+    additionalPlaceholders,
     configMessage,
     github: github.context,
     linkRoot,
@@ -25,7 +33,7 @@ import { templateMessage } from "./template-message.js";
     await notifySlackWebhook(webhook, message.buildToJSON());
   } else {
     console.log("Dry run enabled, printing message instead!");
-    console.log(message);
+    console.log(message.buildToJSON());
   }
 })().catch((e) => {
   console.error(e);

src/reducers.test.ts

@@ -0,0 +1,23 @@
+import { expect, it } from "vitest";
+
+import { reduceAdditionalPlaceholders } from "./reducers.js";
+
+it("reduces a valid input", () => {
+  const input = ["example=example", "test=test", "equals=="];
+
+  expect(reduceAdditionalPlaceholders(input)).toEqual({
+    example: "example",
+    test: "test",
+    equals: "=",
+  });
+});
+
+it("ignores invalid inputs", () => {
+  const input = ["example=example", "test=test", "equals==", "=something", ""];
+
+  expect(reduceAdditionalPlaceholders(input)).toEqual({
+    example: "example",
+    test: "test",
+    equals: "=",
+  });
+});

src/reducers.ts

@@ -0,0 +1,13 @@
+export const reduceAdditionalPlaceholders = (multilineInput: string[]) =>
+  multilineInput.reduce<Record<string, string>>((acc, input) => {
+    const indexOfFirstEquals = input.indexOf("=");
+    if (indexOfFirstEquals < 0) {
+      return acc;
+    }
+    const key = input.substring(0, indexOfFirstEquals);
+    const value = input.substring(indexOfFirstEquals + 1);
+    if (!key) {
+      return acc;
+    }
+    return { ...acc, [key]: value };
+  }, {});

src/template-message.test.ts

@@ -19,6 +19,7 @@ afterEach(() => {
 it("templates a message", () => {
   expect(
     templateMessage({
+      additionalPlaceholders: {},
       configMessage:
         ":rocket: A new [[@linkify(it.links.commitSha, 'version') /]] of [[@linkify(it.links.repository, it.repository) /]] has been deployed!",
       github: fakeGitHubContext,
@@ -28,3 +29,19 @@ it("templates a message", () => {
     ":rocket: A new <https://github.com/singlestone/commit-deploy-slack-action/commit/test|version> of <https://github.com/singlestone/commit-deploy-slack-action|singlestone/commit-deploy-slack-action> has been deployed!",
   );
 });
+
+it("supports additional placeholders", () => {
+  expect(
+    templateMessage({
+      additionalPlaceholders: {
+        "non-production": "https://google.com",
+      },
+      configMessage:
+        ":rocket: A new [[@linkify(it.links.commitSha, 'version') /]] of [[@linkify(it.links.repository, it.repository) /]] has been deployed to [[@linkify(it['non-production'], 'non-production') /]]!",
+      github: fakeGitHubContext,
+      linkRoot: "https://github.com",
+    }),
+  ).toEqual(
+    ":rocket: A new <https://github.com/singlestone/commit-deploy-slack-action/commit/test|version> of <https://github.com/singlestone/commit-deploy-slack-action|singlestone/commit-deploy-slack-action> has been deployed to <https://google.com|non-production>!",
+  );
+});

src/template-message.ts

@@ -2,6 +2,7 @@ import { context } from "@actions/github";
 import { render } from "squirrelly";
 
 interface TemplateMessageParams {
+  additionalPlaceholders: Record<string, string>;
   configMessage: string;
   github: typeof context;
   linkRoot: string;
@@ -21,6 +22,7 @@ export const templateMessage = (params: TemplateMessageParams): string => {
       github: params.github,
       links,
       repository,
+      ...params.additionalPlaceholders,
     },
     {
       tags: ["[[", "]]"],