Detect Scarb version from .tool-versions file

.github/workflows/ci.yml

@@ -9,24 +9,48 @@ on:
 
 jobs:
   test:
-    name: test ${{ matrix.os }} scarb:${{ matrix.scarb-version }}
+    name: test ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         os:
           - ubuntu-latest
           - macos-latest
           - windows-latest
-        scarb-version:
-          - "0.4.1"
-          - latest
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v3
-      - uses: ./
+
+      - name: "Fetch latest Scarb version from GitHub releases"
+        id: version
+        shell: pwsh
+        run: |
+          $location = (Invoke-WebRequest -Uri "https://github.com/software-mansion/scarb/releases/latest" -Method Head -MaximumRedirection 0 -SkipHttpErrorCheck -ErrorAction Ignore).Headers.Location
+          $latest_version = ($location -replace '^.*/v','')
+          echo "Latest Scarb version found is $latest_version"
+          echo "LATEST_VERSION=$latest_version" >> $env:GITHUB_OUTPUT
+
+      - name: "Setup Scarb without `scarb-version`"
+        uses: ./
+      - run: scarb --version | grep "scarb ${{ steps.version.outputs.LATEST_VERSION }}"
+
+      - name: "Setup Scarb with `scarb-version: 0.4.1`"
+        uses: ./
         with:
-          scarb-version: ${{ matrix.scarb-version }}
-      - run: scarb --version
+          scarb-version: 0.4.1
+      - run: scarb --version | grep "scarb 0.4.1"
+
+      - name: "Setup Scarb with `scarb-version: latest`"
+        uses: ./
+        with:
+          scarb-version: latest
+      - run: scarb --version | grep "scarb ${{ steps.version.outputs.LATEST_VERSION }}"
+
+      - name: "Create .tool-versions file"
+        run: echo "scarb 0.5.0" >> .tool-versions
+      - name: "Setup Scarb using `.tool-versions` file"
+        uses: ./
+      - run: scarb --version | grep "scarb 0.5.0"
 
   lint:
     runs-on: ubuntu-latest

action.yml

@@ -7,7 +7,7 @@ branding:
 inputs:
   scarb-version:
     description: Scarb version to use
-    default: "latest"
+    required: false
 outputs:
   scarb-prefix:
     description: The prefix of the installed Scarb

lib/versions.js

@@ -1,22 +1,22 @@
+import fs from "fs/promises";
 import * as core from "@actions/core";
 import { HttpClient } from "@actions/http-client";
 
 export async function determineVersion(repo, versionInput) {
-  versionInput = versionInput.trim();
+  versionInput = versionInput?.trim();
 
-  if (versionInput === "latest") {
-    versionInput = await fetchLatestTag(repo);
-  }
-
-  if (versionInput.startsWith("v")) {
-    versionInput = versionInput.substring(1);
+  if (!versionInput) {
+    let toolVersion = await getVersionFromToolVersionsFile();
+    versionInput = toolVersion ?? "latest";
   }
 
-  if (!versionInput) {
-    throw new Error(`'scarb-input' value must not be empty`);
+  if (versionInput === "latest") {
+    versionInput = await fetchLatestTag(repo);
   }
 
-  return versionInput;
+  return versionInput.startsWith("v")
+    ? versionInput.substring(1)
+    : versionInput;
 }
 
 function fetchLatestTag(repo) {
@@ -60,3 +60,13 @@ function fetchLatestTag(repo) {
     },
   );
 }
+
+async function getVersionFromToolVersionsFile() {
+  try {
+    return (await fs.readFile(".tool-versions", "utf-8")).match(
+      /^scarb ([\w.-]+)/m,
+    )?.[1];
+  } catch (e) {
+    return;
+  }
+}