Merge pull request #25 from SpraxDev/prepare-v1

Prepare for v1

* Use SpraxDev/Spgito-BuildTools by default
* Allow choosing between SpraxDev and SpigotMC BuildTools
* Improve logging and error handling
* Fix build being skipped when only one version should be build
* README.md: Fixed typos and updated description
* Improve GitHub-Actions

.github/workflows/build.yml

@@ -10,24 +10,43 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - run: |
+      - name: Install dependencies and build
+        run: |
           npm i
           npm run build
 
-  # Make sure the action works on a clean machine without building
+  # Make sure the action works on a clean machine without building it
   run:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: ./
+
+      - name: Compile 2 spigot version
+        uses: ./
         with:
           versions: latest, 1.8
 
+      # Run again. The Action should detect that the requested versions are already inside the local maven repo
+      - name: Compile the same versions agains
+        uses: ./
+        with:
+          # These versions should match the ones above
+          versions: latest, 1.8
+
+      - name: Upload logs
+        if: ${{ always() }}
+        uses: actions/upload-artifact@v2
+        with:
+          name: logs
+          path: /tmp/SpraxDev-Action-SpigotMC/logs/
+
   # Run the original BuildTools in GitHub Actions to easily compare the build times etc.
   original-run:
     runs-on: ubuntu-latest
     steps:
       - name: Run original Spigot-BuildTools
+        # These versions should match the ones from the 'run'-job
+        # Using '--compile Spigot' as this action does the same by default
         run: |
           wget https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar -O BuildTools.jar
           java -jar BuildTools.jar --rev latest --compile Spigot

README.md

@@ -18,10 +18,14 @@
   </a>
 </p>
 
-# Action-Spigot
+# Action-SpigotMC
-This Action allows you to easily compile Minecraft Spigot
+This Action allows you to easily compile Minecraft Spigot or Paper
 and install it in your runners local maven repository.
 
+Supported:
+* SpigotMC (using official BuildTools or my modified one)
+* ~~PaperMC~~ (coming soon #26)
+
 You configure all the versions you want, and it'll compile all the missing versions automatically.
 By checking for a file in the local maven repository beforehand, build times can be reduces drastically.
 
@@ -37,7 +41,7 @@ If you don't change them, you can remove them from your workflow,
 as they are set automatically.
 
 ```YAML
-- uses: SpraxDev/Action-Spigot@v1
+- uses: SpraxDev/Action-SpigotMC@v1
   with:
     # A comma-separated list of Spigot version that should be compiled
     # These values are later given to the BuildTools.jar as '--rev' argument
@@ -45,13 +49,6 @@ as they are set automatically.
     # Example: latest, 1.14.4, 1.8.8
     versions: latest
 
-    # A comma-separated list of build targets
-    # This value is later given to the BuildTools.jar as '--compile' argument
-    #
-    # Available: None, Spigot, CraftBukkit
-    # Example: Spigot, CraftBukkit
-    target: Spigot
-
     # Should sources be generated?
     # If enabled, BuildTools is provided the '--generate-source' argument
     generateSrc: false
@@ -72,4 +69,9 @@ as they are set automatically.
     # The amount of builds allowed to run at the same time
     # Set to '-1' to use system's cpu core count
     threads: -1
+
+    # You can choose between different BuildTools to be used by this action
+    # 'SpraxDev' is my fork of SpigotMC's that introduces some changes (https://github.com/SpraxDev/Spigot-BuildTools/#breaking-changes)
+    # Available: SpraxDev, SpigotMC
+    buildToolProvider: SpraxDev
 ```

action.yml

@@ -1,5 +1,5 @@
-name: Compile Minecraft Spigot (BuildTools)
+name: Compile Minecraft Spigot or Paper (BuildTools)
-description: Makes it easier to compile multiple Spigot versions at the same time and speed up clean builds
+description: Makes it easier to compile multiple Spigot/Paper versions at the same time and speed up clean builds
 author: Christian Koop
 
 branding:
@@ -11,10 +11,6 @@ inputs:
     required: false
     default: latest
     description: Versions to build (sperate multiple with ',')
-  target:
-    required: false
-    default: Spigot
-    description: Select what exactly you want to compile (none, Spigot, CraftBukkit) (sperate multiple with ',')
   generateSrc:
     required: false
     default: 'false'
@@ -35,6 +31,10 @@ inputs:
     required: false
     default: '-1'
     description: The amount of builds allowed to run at a time, set to '-1' to use system's cpu count
+  buildToolProvider:
+    required: false
+    default: SpraxDev
+    description: Whose BuildTool should be used? (SpraxDev [default], SpigotMC)
 
 runs:
   using: node12

dist/package.json

@@ -33,12 +33,14 @@
     "@actions/core": "^1.2.6",
     "async": "^3.2.0",
     "fs-extra": "^9.0.1",
-    "read-last-lines": "^1.7.2"
+    "n-readlines": "^1.0.1",
+    "xml-js": "^1.6.11"
   },
   "devDependencies": {
     "@tsconfig/node12": "^1.0.7",
     "@types/async": "^3.2.4",
     "@types/fs-extra": "^9.0.4",
+    "@types/n-readlines": "^1.0.1",
     "@types/node": "~12.19.6",
     "@vercel/ncc": "^0.25.1",
     "ts-node": "^9.0.0",

package-lock.json

@@ -30,6 +30,15 @@
         "@types/node": "*"
       }
     },
+    "@types/n-readlines": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/@types/n-readlines/-/n-readlines-1.0.1.tgz",
+      "integrity": "sha512-n1ND4k+9hgtil2HnHK+1tIj1UWchsD+RwoH7eVQqLbUe8AxwLuqDEnx3Riq+twHoMTjP80Q/ilB3LGdyXKfTEg==",
+      "dev": true,
+      "requires": {
+        "@types/node": "*"
+      }
+    },
     "@types/node": {
       "version": "12.19.6",
       "resolved": "https://registry.npmjs.org/@types/node/-/node-12.19.6.tgz",
@@ -42,11 +51,6 @@
       "integrity": "sha512-dGecC5+1wLof1MQpey4+6i2KZv4Sfs6WfXkl9KfO32GED4ZPiKxRfvtGPjbjZv0IbqMl6CxtcV1RotXYfd5SSA==",
       "dev": true
     },
-    "any-promise": {
-      "version": "1.3.0",
-      "resolved": "https://registry.npmjs.org/any-promise/-/any-promise-1.3.0.tgz",
-      "integrity": "sha1-q8av7tzqUugJzcA3au0845Y10X8="
-    },
     "arg": {
       "version": "4.1.3",
       "resolved": "https://registry.npmjs.org/arg/-/arg-4.1.3.tgz",
@@ -113,28 +117,15 @@
       "integrity": "sha512-s8UhlNe7vPKomQhC1qFelMokr/Sc3AgNbso3n74mVPA5LTZwkB9NlXf4XPamLxJE8h0gh73rM94xvwRT2CVInw==",
       "dev": true
     },
-    "mz": {
+    "n-readlines": {
-      "version": "2.7.0",
+      "version": "1.0.1",
-      "resolved": "https://registry.npmjs.org/mz/-/mz-2.7.0.tgz",
+      "resolved": "https://registry.npmjs.org/n-readlines/-/n-readlines-1.0.1.tgz",
-      "integrity": "sha512-z81GNO7nnYMEhrGh9LeymoE4+Yr0Wn5McHIZMK5cfQCl+NDX08sCZgUc9/6MHni9IWuFLm1Z3HTCXu2z9fN62Q==",
+      "integrity": "sha512-z4SyAIVgMy7CkgsoNw7YVz40v0g4+WWvvqy8+ZdHrCtgevcEO758WQyrYcw3XPxcLxF+//RszTz/rO48nzD0wQ=="
-      "requires": {
-        "any-promise": "^1.0.0",
-        "object-assign": "^4.0.1",
-        "thenify-all": "^1.0.0"
-      }
     },
-    "object-assign": {
+    "sax": {
-      "version": "4.1.1",
+      "version": "1.2.4",
-      "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
+      "resolved": "https://registry.npmjs.org/sax/-/sax-1.2.4.tgz",
-      "integrity": "sha1-IQmtx5ZYh8/AXLvUQsrIv7s2CGM="
+      "integrity": "sha512-NqVDv9TpANUjFm0N8uM5GxL36UgKi9/atZw+x7YFnQ8ckwFGKrl4xX4yWtrey3UJm5nP1kUbnYgLopqWNSRhWw=="
-    },
-    "read-last-lines": {
-      "version": "1.7.2",
-      "resolved": "https://registry.npmjs.org/read-last-lines/-/read-last-lines-1.7.2.tgz",
-      "integrity": "sha512-K0yUvTYAYn6qpyLJufaJ7yC6BeL23qpgZ8SKM7/fA1R1rHotCDxB/zDp9i1I2JHvexWBW6/35jkt07iiIKKp4g==",
-      "requires": {
-        "mz": "^2.7.0"
-      }
     },
     "source-map": {
       "version": "0.6.1",
@@ -152,22 +143,6 @@
         "source-map": "^0.6.0"
       }
     },
-    "thenify": {
-      "version": "3.3.1",
-      "resolved": "https://registry.npmjs.org/thenify/-/thenify-3.3.1.tgz",
-      "integrity": "sha512-RVZSIV5IG10Hk3enotrhvz0T9em6cyHBLkH/YAZuKqd8hRkKhSfCGIcP2KUY0EPxndzANBmNllzWPwak+bheSw==",
-      "requires": {
-        "any-promise": "^1.0.0"
-      }
-    },
-    "thenify-all": {
-      "version": "1.6.0",
-      "resolved": "https://registry.npmjs.org/thenify-all/-/thenify-all-1.6.0.tgz",
-      "integrity": "sha1-GhkY1ALY/D+Y+/I02wvMjMEOlyY=",
-      "requires": {
-        "thenify": ">= 3.1.0 < 4"
-      }
-    },
     "ts-node": {
       "version": "9.0.0",
       "resolved": "https://registry.npmjs.org/ts-node/-/ts-node-9.0.0.tgz",
@@ -192,6 +167,14 @@
       "resolved": "https://registry.npmjs.org/universalify/-/universalify-1.0.0.tgz",
       "integrity": "sha512-rb6X1W158d7pRQBg5gkR8uPaSfiids68LTJQYOtEUhoJUWBdaQHsuT/EUduxXYxcrt4r5PJ4fuHW1MHT6p0qug=="
     },
+    "xml-js": {
+      "version": "1.6.11",
+      "resolved": "https://registry.npmjs.org/xml-js/-/xml-js-1.6.11.tgz",
+      "integrity": "sha512-7rVi2KMfwfWFl+GpPg6m80IVMWXLRjO+PxTq7V2CDhoGak0wzYzFgUY2m4XJ47OGdXd8eLE8EmwfAmdjw7lC1g==",
+      "requires": {
+        "sax": "^1.2.4"
+      }
+    },
     "yn": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/yn/-/yn-3.1.1.tgz",

package.json

@@ -33,12 +33,14 @@
     "@actions/core": "^1.2.6",
     "async": "^3.2.0",
     "fs-extra": "^9.0.1",
-    "read-last-lines": "^1.7.2"
+    "n-readlines": "^1.0.1",
+    "xml-js": "^1.6.11"
   },
   "devDependencies": {
     "@tsconfig/node12": "^1.0.7",
     "@types/async": "^3.2.4",
     "@types/fs-extra": "^9.0.4",
+    "@types/n-readlines": "^1.0.1",
     "@types/node": "~12.19.6",
     "@vercel/ncc": "^0.25.1",
     "ts-node": "^9.0.0",

src/index.ts

@@ -1,63 +1,96 @@
 import * as core from '@actions/core';
-import { join as joinPath, resolve as resolvePath } from 'path';
-import { copy } from 'fs-extra';
-import { rmdirSync } from 'fs';
-
-import { cpuCount, downloadFile, exit, fixArgArr, isNumeric, resetWorkingDir, runCmd } from './utils';
 import { parallelLimit } from 'async';
+import { createWriteStream, existsSync, rmdirSync } from 'fs';
+import { copy } from 'fs-extra';
+import { join as joinPath, resolve as resolvePath } from 'path';
+import { xml2js } from 'xml-js';
 
+import {
+  cpuCount,
+  downloadFile,
+  exit,
+  fixArgArr,
+  isNumeric,
+  readLastLines,
+  resetWorkingDir,
+  runCmd,
+  userHomeDir
+} from './utils';
 
-const rll = require('read-last-lines');
+const supportedBuildTools: { [key: string]: { url: string, prepareArgs: string[] } } = {
+  spraxdev: {
+    url: 'https://github.com/SpraxDev/Spigot-BuildTools/releases/latest/download/BuildTools.jar',
+    prepareArgs: ['--exit-after-fetch']
+  },
+  spigotmc: {
+    url: 'https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar',
+    prepareArgs: ['--compile', 'None']
+  }
+};
 
 /* GitHub Actions inputs */
-const versions: string[] = fixArgArr((core.getInput('versions') || 'latest').split(','));
+const buildToolProvider: string = (core.getInput('buildToolProvider') || 'SpraxDev').toLowerCase();
-const target: string[] = fixArgArr((core.getInput('target') || 'Spigot').toUpperCase().split(','));
+let versions: string[] = fixArgArr((core.getInput('versions') || 'latest').toLowerCase().split(','));
 const generateSrc: boolean = core.getInput('generateSrc') == 'true';
 const generateDoc: boolean = core.getInput('generateDoc') == 'true';
 const disableJavaCheck: boolean = core.getInput('disableJavaCheck') == 'true';
 
-const forceRun: boolean = core.getInput('forceRun') == 'true';  // TODO
+const forceRun: boolean = core.getInput('forceRun') == 'true';
 const threadCount: number = isNumeric(core.getInput('threads')) ? parseInt(core.getInput('threads')) : cpuCount;
 
 const workingDir = resetWorkingDir();
+const appLogFile = joinPath(workingDir.logs, 'SpraxDev_Actions-SpigotMC.log');
+const appLogStream = createWriteStream(appLogFile, {encoding: 'utf-8', flags: 'a' /* append */});
 
 async function run(): Promise<{ code: number, msg?: string }> {
-  return new Promise<{ code: number, msg?: string }>(async (resolve, reject): Promise<void> => {
+  return new Promise(async (resolve, reject): Promise<void> => {
+    try {
       if (versions.length == 0) return resolve({code: 0, msg: 'No version(s) provided to build'});
-    if (target.length == 0) return resolve({code: 0, msg: 'No target(s) provided to build'});
 
-    const appLogFile = joinPath(workingDir.logs, 'SpraxDev_Actions-SpigotMC.log');
+      if (!Object.keys(supportedBuildTools).includes(buildToolProvider)) {
+        return reject(new Error(`'${buildToolProvider}' is not a valid BuildTool-Provider (${Object.keys(supportedBuildTools).join(', ')})`));
+      }
 
-    console.log('Installed Java-Version:');
+      if (!forceRun) {
-    await runCmd('java', ['-version'], workingDir.base, appLogFile);
+        versions = await removeExistingVersions(versions, (ver, jarPath) => {
+          logInfo(`Skipping version '${ver}' because it has been found in the local maven repository: ${jarPath}`);
+        });
 
-    console.log(`Downloading BuildTools.jar from 'hub.spigotmc.org'...`);
+        if (versions.length == 0) return resolve({code: 0, msg: 'No new versions to build'});
-    await downloadFile('https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar', joinPath(workingDir.cache, 'BuildTools.jar'));
+      }
+
+      const buildTool = supportedBuildTools[buildToolProvider];
+
+      logInfo('Installed Java-Version:');
+      await runCmd('java', ['-version'], workingDir.base, appLogStream);
+
+      logInfo(`\nDownloading '${buildTool.url}'...`);
+      await downloadFile(buildTool.url, joinPath(workingDir.cache, 'BuildTools.jar'));
 
       const gotTemplateDirectory = versions.length != 1;
 
       // Prepare template directory if more than one version is provided
       if (gotTemplateDirectory) {
-      console.log('Prepare for future tasks by running BuildTools...');
+        logInfo('Prepare for future tasks by running BuildTools...');
 
-      try {
         await core.group('Prepare BuildTools', async (): Promise<void> => {
-          return runCmd('java', ['-jar', 'BuildTools.jar', '--compile', 'NONE', (disableJavaCheck ? '--disable-java-check' : '')],
+          try {
-              workingDir.cache, appLogFile);
+            return runCmd('java', ['-jar', 'BuildTools.jar', (disableJavaCheck ? '--disable-java-check' : ''), ...buildTool.prepareArgs],
-        });
+                workingDir.cache, appLogStream);
           } catch (err) {
-        console.error(err);
+            logError(err);
 
-        console.error(`\nPrinting last 25 lines from '${resolvePath(appLogFile)}':`);
+            logError(`\nPrinting last 30 lines from '${resolvePath(appLogFile)}':`);
-        for (const line of (await rll.read(appLogFile, 25))) {
+            for (const line of readLastLines(appLogFile, 30)) {
-          console.error(line);
+              logError(line);
             }
 
             return exit(1);
           }
+        });
       }
 
-    const buildToolsArgs = ['-jar', 'BuildTools.jar', '--compile', target.join(',')];
+      const buildToolsArgs = ['-jar', 'BuildTools.jar', '--compile', 'Spigot'];
 
       if (generateSrc) {
         buildToolsArgs.push('--generate-source');
@@ -73,58 +106,120 @@ async function run(): Promise<{ code: number, msg?: string }> {
 
       const tasks = [];
       for (const ver of versions) {
-      tasks.push((callback: (err?: Error, result?: unknown) => void) => {
+        tasks.push(async (): Promise<void> => {
-        try {
+          return new Promise(async (resolveTask, rejectTask): Promise<void> => {
             const start = Date.now();
 
             const logFile = joinPath(workingDir.logs, `${ver}.log`);
 
-          console.log(`Building version '${ver}'...`);
+            logInfo(`Building version '${ver}'...`);
 
             // If there is only one version to build, the cache directory is used instead of copying it first
             const versionDir = gotTemplateDirectory ? joinPath(workingDir.base, `${ver}`) : workingDir.cache;
 
             if (gotTemplateDirectory) {
-            copy(workingDir.cache, versionDir)
+              await copy(workingDir.cache, versionDir);
-                .then(() => {
+            }
-                  runCmd('java', [...buildToolsArgs, '--rev', ver],
+
-                      versionDir, logFile, true)  // set to silent because multiple builds can run at once
+            try {
-                      .then(() => {
+              // set to silent because multiple builds can run at once
+              await runCmd('java', [...buildToolsArgs, '--rev', ver], versionDir, logFile, true);
+
+              if (gotTemplateDirectory) {
                 rmdirSync(versionDir, {recursive: true}); // delete our task dir
+              }
 
               const end = Date.now();
 
-                        console.log(`Finished building '${ver}' in ${((end - start) / 60_000)} minutes`);
+              logInfo(`Finished '${ver}' in ${((end - start) / 60_000).toFixed(2)} minutes`);
-                        callback();
+              resolveTask();
-                      });
+            } catch (err) {
-                })
+              logInfo(`An error occurred while building '${ver}'`);
-                .catch((err) => {
+              logError(err);
-                  console.log(`An error occurred while building '${ver}'`);
-                  console.error(err);
 
-                  console.error(`\nPrinting last 25 lines from '${resolvePath(logFile)}':`);
+              logError(`\nPrinting last 30 lines from '${resolvePath(logFile)}':`);
-                  rll.read(logFile, 25)
+
-                      .then((lines: string[]) => {
+              for (const line of readLastLines(logFile, 30)) {
-                        for (const line of lines) {
+                logError(line);
-                          console.error(line);
+              }
+
+              rejectTask(err);
             }
-                      })
-                      .catch(console.error)
-                      .finally(() => callback(err));
           });
+        });
+      }
+
+      parallelLimit(tasks, threadCount, (err) => {
+        if (err) return reject(err);
+
+        resolve({code: 0});
+      });
+    } catch (err) {
+      reject(err);
+    }
+  });
+}
+
+async function removeExistingVersions(versionArr: string[], onExist: (ver: string, jarPath: string) => void): Promise<string[]> {
+  return new Promise(async (resolve, _reject): Promise<void> => {
+    const result = [];
+
+    for (const ver of versionArr) {
+      let skipVersion = false;
+      let versionToCheck: string | null = ver != 'latest' ? ver : null;
+
+      try {
+        const verJsonBuff = await downloadFile(`https://hub.spigotmc.org/versions/${ver}.json`, null);
+        const verJson = verJsonBuff instanceof Buffer ? JSON.parse(verJsonBuff.toString('utf-8')) : null;
+        const bukkitRef: undefined | string = verJson?.refs?.Bukkit;
+
+        if (bukkitRef) {
+          const verPomBuff = await downloadFile(`https://hub.spigotmc.org/stash/projects/SPIGOT/repos/bukkit/raw/pom.xml?at=${bukkitRef}`, null);
+
+          if (verPomBuff instanceof Buffer) {
+            const result = xml2js(verPomBuff.toString('utf-8'), {
+              compact: true,
+              ignoreComment: true,
+              ignoreAttributes: true
+            }) as any;
+
+            versionToCheck = result.project?.version?._text;
+          }
         }
       } catch (err) {
-          callback(err);
+        logError(err);
-        }
-      });
       }
 
-    (parallelLimit(tasks, threadCount) as unknown as Promise<unknown[]>)  // Valid according to docs - types outdated?
+      const jarPath = resolvePath(joinPath(userHomeDir, `/.m2/repository/org/spigotmc/spigot/${versionToCheck}/spigot-${versionToCheck}.jar`));
-        .then(() => resolve({code: 0}))
+      if (versionToCheck) {
-        .catch(reject);
+        skipVersion = existsSync(jarPath);
+      }
+
+      if (skipVersion) {
+        onExist(ver, jarPath);
+      } else {
+        result.push(ver);
+      }
+    }
+
+    resolve(result);
   });
 }
 
+export function logInfo(msg?: string): void {
+  console.log(msg);
+  appLogStream.write(msg + '\n');
+}
+
+export function logError(msg?: string | object): void {
+  if (typeof msg != 'string') {
+    msg = JSON.stringify(msg, null, 2);
+  }
+
+  console.error(msg);
+  appLogStream.write(msg + '\n');
+}
+
 run()
     .then((result) => exit(result.code, result.msg))
     .catch((err) => exit(1, err));

src/utils.ts

@@ -1,14 +1,17 @@
 import { spawn as spawnProcess } from 'child_process';
-import { join as joinPath } from 'path';
+import { createWriteStream, mkdirSync, readFileSync, rmdirSync, WriteStream } from 'fs';
 import { get as httpGet } from 'http';
 import { get as httpsGet } from 'https';
-import { cpus, tmpdir } from 'os';
+import readLines from 'n-readlines';
-import { createWriteStream, mkdirSync, readFileSync, rmdirSync, WriteStream } from 'fs';
+import { cpus, homedir, tmpdir } from 'os';
+import { join as joinPath } from 'path';
+import { logError, logInfo } from './index';
 
 const packageJson = JSON.parse(readFileSync(joinPath(__dirname, '..', 'package.json'), 'utf-8'));
-const userAgent = `${packageJson.name || 'Action-SpigotMC'}/${packageJson.version || 'UNKNOWN_VERSION'} (+${packageJson.homepage || 'https://github.com/SpraxDev/'})`;
+const userAgent = `${packageJson.name || 'Action-SpigotMC'}/${packageJson.version || 'UNKNOWN_VERSION'} (+${packageJson.homepage || 'https://github.com/SpraxDev/Action-SpigotMC'})`;
 
 export const cpuCount = cpus().length;
+export const userHomeDir = homedir();
 
 export function fixArgArr(arr: string[]): string[] {
   const result: string[] = [];
@@ -28,9 +31,12 @@ export function isNumeric(str: string): boolean {
   return /^[0-9]+$/.test(str);
 }
 
-export async function runCmd(cmd: string, args: string[], workingDir: string, logFile: string, silent: boolean = false): Promise<void> {
+export async function runCmd(cmd: string, args: string[], workingDir: string, logStreamOrFile: string | WriteStream, silent: boolean = false): Promise<void> {
   return new Promise((resolve, reject) => {
-    const logStream = createWriteStream(logFile, {encoding: 'utf-8', flags: 'a'});  // Use UTF-8 and append when file exists
+    const closeLogStream = typeof logStreamOrFile == 'string';
+    const logStream = typeof logStreamOrFile != 'string' ? logStreamOrFile :
+        createWriteStream(logStreamOrFile, {encoding: 'utf-8', flags: 'a' /* append */});
+
     const runningProcess = spawnProcess(cmd, args, {shell: true, cwd: workingDir, env: process.env});
 
     runningProcess.stdout.on('data', (data) => {
@@ -49,7 +55,9 @@ export async function runCmd(cmd: string, args: string[], workingDir: string, lo
     });
 
     runningProcess.on('close', (code) => {
+      if (closeLogStream) {
         logStream.close();
+      }
 
       if (code != 0) {
         return reject({err: new Error(`process exited with code ${code}`), cmd, workingDir});
@@ -60,35 +68,57 @@ export async function runCmd(cmd: string, args: string[], workingDir: string, lo
   });
 }
 
-export async function downloadFile(url: string, dest: string): Promise<void> {
+/**
-  const getURL = url.toLowerCase().startsWith('http://') ? httpGet : httpsGet;
+ * @param url The URL to fetch the data from
+ * @param dest Set to `null` to get an Buffer instead of writing it to the file system
+ * @param currRedirectDepth Internally used to track how often the function has been redirected
+ */
+export async function downloadFile(url: string, dest: string | null, currRedirectDepth: number = 0): Promise<Buffer | void> {
+  const doGetRequest = url.toLowerCase().startsWith('http://') ? httpGet : httpsGet;
 
   return new Promise((resolve, reject) => {
     let writeStream: WriteStream | null = null;
 
-    const done = function (err: boolean) {
+    const done = function (errored: boolean) {
       if (writeStream) {
         writeStream.close();
         writeStream = null;
 
-        if (err) {
+        if (errored && dest != null) {
           rmdirSync(dest, {recursive: true});
         }
       }
     };
 
-    // TODO
+    doGetRequest(url, {
-    getURL(url, {
       headers: {
         'User-Agent': userAgent
       }
     }, (httpRes) => {
       if (httpRes.statusCode != 200) {
+        const locHeader = httpRes.headers.location;
+
+        // Follow redirect
+        if (currRedirectDepth < 12 && locHeader &&
+            (httpRes.statusCode == 301 || httpRes.statusCode == 302 || httpRes.statusCode == 303 ||
+                httpRes.statusCode == 307 || httpRes.statusCode == 308)) {
+          done(false);
+
+          if (!/https?:\/\//g.test(locHeader)) {
+            return reject(new Error(`Server responded with ${httpRes.statusCode} and a relative Location-Header value (${locHeader})`));
+          }
+
+          return downloadFile(locHeader, dest, ++currRedirectDepth)
+              .then(resolve)
+              .catch(reject);
+        } else {
           done(true);
 
           return reject(new Error(`Server responded with ${httpRes.statusCode}`));
         }
+      }
 
+      if (dest != null) {
         writeStream = createWriteStream(dest, {encoding: 'binary'})
             .on('finish', () => {
               done(false);
@@ -102,6 +132,17 @@ export async function downloadFile(url: string, dest: string): Promise<void> {
             });
 
         httpRes.pipe(writeStream);
+      } else {
+        const chunks: Buffer[] = [];
+
+        httpRes.on('data', (chunk) => {
+          chunks.push(Buffer.from(chunk, 'binary'));
+        });
+
+        httpRes.on('end', () => {
+          resolve(Buffer.concat(chunks));
+        });
+      }
     })
         .on('error', (err) => {
           done(true);
@@ -111,6 +152,23 @@ export async function downloadFile(url: string, dest: string): Promise<void> {
   });
 }
 
+export function readLastLines(file: string, lineCount: number, encoding: string = 'utf-8'): string[] {
+  const result = [];
+
+  const reader = new readLines(file);
+
+  let line;
+  while (line = reader.next()) {
+    result.push(line.toString(encoding));
+
+    if (result.length > lineCount) {
+      result.shift();
+    }
+  }
+
+  return result;
+}
+
 export function resetWorkingDir(): { base: string, cache: string, logs: string } {
   const baseDir = joinPath(tmpdir(), 'SpraxDev-Action-SpigotMC');
   const cacheDir = joinPath(baseDir, 'cache');
@@ -128,9 +186,9 @@ export function resetWorkingDir(): { base: string, cache: string, logs: string }
 export function exit(code: number, msg?: string | Error): never {
   if (msg) {
     if (typeof msg == 'string') {
-      console.log(msg);
+      logInfo(msg);
     } else {
-      console.error(msg);
+      logError(msg);
     }
   }