diff --git a/src/utils/logging/process-logger.ts b/src/utils/logging/process-logger.ts
new file mode 100644
index 0000000..d5f134e
--- /dev/null
+++ b/src/utils/logging/process-logger.ts
@@ -0,0 +1,131 @@
+import { DEFAULT_NEWLINE } from "@/utils/environment";
+import { Logger } from "./logger";
+
+/**
+ * Represents a delegate type that consumes log messages.
+ */
+interface LogConsumer {
+ /**
+ * Processes a given log message.
+ *
+ * @param message - A log message to process.
+ */
+ (message: string): void;
+}
+
+/**
+ * The `process` object provides information about, and control over, the current Node.js process.
+ */
+interface Process {
+ /**
+ * A stream connected to `stdout` (fd `1`).
+ */
+ stdout?: {
+ /**
+ * Sends data on the socket.
+ */
+ write: LogConsumer;
+ };
+}
+
+/**
+ * A logger implementation that dumps formatted log messages to `stdout`.
+ *
+ * Compatible with GitHub Actions.
+ *
+ * @remarks
+ *
+ * https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-a-debug-message
+ */
+export class ProcessLogger implements Logger {
+ /**
+ * A function to consume produced log messages.
+ */
+ private readonly _logConsumer: LogConsumer;
+
+ /**
+ * The newline sequence to use when writing logs.
+ */
+ private readonly _newline: string;
+
+ /**
+ * Constructs a new {@link ProcessLogger} instance.
+ *
+ * @param process - The process this logger is attached to. Defaults to `globalThis.process`.
+ * @param newline - The newline sequence to use when writing logs. Defaults to `os.EOL`.
+ */
+ constructor(process?: Process, newline?: string);
+
+ /**
+ * Constructs a new {@link ProcessLogger} instance.
+ *
+ * @param logConsumer - The function to consume log messages.
+ * @param newline - The newline sequence to use when writing logs. Defaults to `os.EOL`.
+ */
+ constructor(logConsumer: LogConsumer, newline?: string);
+
+ /**
+ * Constructs a new {@link ProcessLogger} instance.
+ *
+ * @param processOrLogConsumer - A process this logger is attached to, or a function to consume log messages.
+ * @param newline - The newline sequence to use when writing logs. Defaults to `os.EOL`.
+ */
+ constructor(processOrLogConsumer: Process | LogConsumer, newline?: string) {
+ if (typeof processOrLogConsumer === "function") {
+ this._logConsumer = processOrLogConsumer;
+ } else {
+ const process = processOrLogConsumer ?? globalThis.process;
+ this._logConsumer =
+ typeof process.stdout?.write === "function"
+ ? msg => process.stdout.write(msg)
+ : (() => {});
+ }
+ this._newline = newline ?? DEFAULT_NEWLINE;
+ }
+
+ /**
+ * @inheritdoc
+ */
+ fatal(message: string | Error): void {
+ this.error(message);
+ }
+
+ /**
+ * @inheritdoc
+ */
+ error(message: string | Error): void {
+ this.log(message, "error")
+ }
+
+ /**
+ * @inheritdoc
+ */
+ warn(message: string | Error): void {
+ this.log(message, "warning")
+ }
+
+ /**
+ * @inheritdoc
+ */
+ info(message: string | Error): void {
+ this.log(message);
+ }
+
+ /**
+ * @inheritdoc
+ */
+ debug(message: string | Error): void {
+ this.log(message, "debug");
+ }
+
+ /**
+ * Logs a message with an optional log level.
+ *
+ * @param message - The message to log.
+ * @param level - Optional log level string.
+ */
+ private log(message: string | Error, level?: string): void {
+ const cmd = level ? `::${level}::` : "";
+ this._logConsumer(`${cmd}${message}${this._newline}`);
+ }
+}
diff --git a/tests/unit/utils/logging/process-logger.spec.ts b/tests/unit/utils/logging/process-logger.spec.ts
new file mode 100644
index 0000000..4745232
--- /dev/null
+++ b/tests/unit/utils/logging/process-logger.spec.ts
@@ -0,0 +1,129 @@
+import { ProcessLogger } from "@/utils/logging/process-logger";
+
+interface MockProcess {
+ stdout: {
+ write: jest.Mock;
+ };
+}
+
+function createMockProcess(): MockProcess {
+ return {
+ stdout: {
+ write: jest.fn(),
+ },
+ };
+}
+
+describe("ProcessLogger", () => {
+ describe("constructor", () => {
+ test("constructs a new instance with the provided process", () => {
+ const process = createMockProcess();
+ const logger = new ProcessLogger(process, "\n");
+
+ logger.info("Info");
+
+ expect(process.stdout.write).toHaveBeenCalledTimes(1);
+ expect(process.stdout.write).toHaveBeenCalledWith("Info\n");
+ });
+
+ test("constructor uses provided newline sequence", () => {
+ const process = createMockProcess();
+ const logger = new ProcessLogger(process, "\n\n");
+
+ logger.info("Info");
+
+ expect(process.stdout.write).toHaveBeenCalledTimes(1);
+ expect(process.stdout.write).toHaveBeenCalledWith("Info\n\n");
+ });
+
+ test("constructor uses provided log consumer", () => {
+ const logConsumer = jest.fn();
+ const logger = new ProcessLogger(logConsumer, "\n");
+
+ logger.info("Info");
+
+ expect(logConsumer).toHaveBeenCalledTimes(1);
+ expect(logConsumer).toHaveBeenCalledWith("Info\n");
+ });
+
+ test("constructor uses provided log consumer and newline sequence", () => {
+ const logConsumer = jest.fn();
+ const logger = new ProcessLogger(logConsumer, "\n\n");
+
+ logger.info("Info");
+
+ expect(logConsumer).toHaveBeenCalledTimes(1);
+ expect(logConsumer).toHaveBeenCalledWith("Info\n\n");
+ });
+ });
+
+ describe("fatal", () => {
+ test("redirects the call to process.stdout.write", () => {
+ const process = createMockProcess();
+ const logger = new ProcessLogger(process, "\n");
+
+ logger.fatal("Fatal Error");
+ logger.fatal(new Error("Fatal Error"));
+
+ expect(process.stdout.write).toHaveBeenCalledTimes(2);
+ expect(process.stdout.write).toHaveBeenNthCalledWith(1, "::error::Fatal Error\n");
+ expect(process.stdout.write).toHaveBeenNthCalledWith(2, "::error::Error: Fatal Error\n");
+ });
+ });
+
+ describe("error", () => {
+ test("redirects the call to process.stdout.write", () => {
+ const process = createMockProcess();
+ const logger = new ProcessLogger(process, "\n");
+
+ logger.error("Error");
+ logger.error(new Error("Error"));
+
+ expect(process.stdout.write).toHaveBeenCalledTimes(2);
+ expect(process.stdout.write).toHaveBeenNthCalledWith(1, "::error::Error\n");
+ expect(process.stdout.write).toHaveBeenNthCalledWith(2, "::error::Error: Error\n");
+ });
+ });
+
+ describe("warn", () => {
+ test("redirects the call to process.stdout.write", () => {
+ const process = createMockProcess();
+ const logger = new ProcessLogger(process, "\n");
+
+ logger.warn("Warning");
+ logger.warn(new Error("Warning"));
+
+ expect(process.stdout.write).toHaveBeenCalledTimes(2);
+ expect(process.stdout.write).toHaveBeenNthCalledWith(1, "::warning::Warning\n");
+ expect(process.stdout.write).toHaveBeenNthCalledWith(2, "::warning::Error: Warning\n");
+ });
+ });
+
+ describe("info", () => {
+ test("redirects the call to process.stdout.write", () => {
+ const process = createMockProcess();
+ const logger = new ProcessLogger(process, "\n");
+
+ logger.info("Info");
+ logger.info(new Error("Info"));
+
+ expect(process.stdout.write).toHaveBeenCalledTimes(2);
+ expect(process.stdout.write).toHaveBeenNthCalledWith(1, "Info\n");
+ expect(process.stdout.write).toHaveBeenNthCalledWith(2, "Error: Info\n");
+ });
+ });
+
+ describe("debug", () => {
+ test("redirects the call to process.stdout.write", () => {
+ const process = createMockProcess();
+ const logger = new ProcessLogger(process, "\n");
+
+ logger.debug("Debug Info");
+ logger.debug(new Error("Debug Info"));
+
+ expect(process.stdout.write).toHaveBeenCalledTimes(2);
+ expect(process.stdout.write).toHaveBeenNthCalledWith(1, "::debug::Debug Info\n");
+ expect(process.stdout.write).toHaveBeenNthCalledWith(2, "::debug::Error: Debug Info\n");
+ });
+ });
+});