deno compile for standalone executables - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does deno compile do?

It creates a standalone executable from your Deno script that can run without needing Deno installed.

beginner

Which command compiles a Deno script into a standalone executable?

deno compile --unstable --output myapp myscript.ts

This compiles myscript.ts into an executable named myapp.

intermediate

Why use the --unstable flag with deno compile?

Because the compile feature is still marked unstable and requires this flag to enable it.

beginner

What is a benefit of a standalone executable created by Deno?

It can run on a machine without Deno installed, making distribution easier like sharing a simple app.

intermediate

Can you compile Deno scripts for different operating systems?

Yes, by specifying the --target flag you can build executables for Windows, macOS, or Linux.

What does deno compile produce?

A A Docker container

B A JavaScript bundle

C A standalone executable file

D A Deno script with comments removed

deno compile creates a standalone executable that runs without Deno.

Which flag is required to use deno compile?

A --unstable

B --allow-net

C --watch

D --reload

The compile feature is unstable and requires the --unstable flag.

How do you specify the output file name when compiling?

A --target

B --name

C --file

D --output

Use --output to set the executable's file name.

Can a Deno compiled executable run on a machine without Deno installed?

A No

B Yes

C Only if Deno is installed

D Only on Linux

Standalone executables run independently of Deno.

Which flag lets you build for a different OS?

A --target

B --platform

C --os

D --arch

The --target flag sets the OS and architecture for the executable.

Explain how to create a standalone executable from a Deno script and why it might be useful.

Think about how you share apps with friends who don't have Deno.

Describe how to compile a Deno script for a different operating system.

Consider building for Windows from macOS.

Practice

1. What is the main purpose of the deno compile command?

easy

A. To create a standalone executable from a Deno script

B. To install Deno on your computer

C. To run a Deno script without compiling

D. To update Deno to the latest version

Solution

1. Step 1: Understand the role of deno compile

   This command packages a Deno script into a single executable file that can run without needing Deno installed.

2. Step 2: Compare other options

   Installing Deno, running scripts without compiling, or updating Deno are done by different commands, not deno compile.

3. Final Answer:

   To create a standalone executable from a Deno script -> Option A

4. Quick Check:

   deno compile = create executable [OK]

Hint: Remember: compile means make a runnable file [OK]

Common Mistakes:

• Confusing compile with install
• Thinking compile runs scripts directly
• Mixing compile with update commands

2. Which of the following is the correct syntax to compile a Deno script named app.ts into a standalone executable named app.exe on Windows?

easy

A. deno run --output app.exe app.ts

B. deno compile --output app.exe app.ts

C. deno build app.ts -o app.exe

D. deno compile app.ts --exe app.exe

Solution

1. Step 1: Recall the correct deno compile syntax

   The command uses deno compile --output [filename] [script] to specify output executable and source file.

2. Step 2: Check other options for errors

   deno run runs scripts but does not compile; deno build is not a valid command; --exe is not a recognized flag.

3. Final Answer:

   deno compile --output app.exe app.ts -> Option B

4. Quick Check:

   compile + --output + script = correct syntax [OK]

Hint: Use --output to name your executable [OK]

Common Mistakes:

• Using deno run instead of deno compile
• Wrong flag like --exe instead of --output
• Mixing command order

3. Given the command deno compile --output hello hello.ts and hello.ts contains console.log('Hello Deno!');, what will happen when you run the generated executable?

medium

A. It opens a browser window

B. It throws a syntax error

C. It does nothing

D. It prints 'Hello Deno!' to the console

Solution

1. Step 1: Understand the compiled executable behavior

   The executable runs the script code, so it will print the message to the console.

2. Step 2: Eliminate incorrect options

   No syntax error occurs because the script is valid; it does not open a browser or stay silent.

3. Final Answer:

   It prints 'Hello Deno!' to the console -> Option D

4. Quick Check:

   Compiled script output = printed message [OK]

Hint: Compiled executable runs script code as is [OK]

Common Mistakes:

• Expecting compile to change output
• Thinking compile causes errors
• Assuming GUI opens automatically

4. You tried to compile your script with deno compile --output myapp myapp.ts but got an error: PermissionDenied: read access to file 'myapp.ts' is required. What is the best way to fix this?

medium

A. Add --allow-read flag to the compile command

B. Run the command as administrator

C. Add --allow-run flag to the compile command

D. Rename the script file to myapp.js

Solution

1. Step 1: Understand the permission error

   The error says read access is denied for the script file, which is required to compile the source file.

2. Step 2: Identify correct permission flag

   --allow-read grants permission to read files, which is required to compile the script.

3. Final Answer:

   Add --allow-read flag to the compile command -> Option A

4. Quick Check:

   PermissionDenied = missing --allow-read [OK]

Hint: Use --allow-read to fix file access errors [OK]

Common Mistakes:

• Using --allow-run instead of --allow-read
• Thinking admin rights fix permission errors
• Renaming file without fixing permissions

5. You want to create a standalone executable for Linux from a Deno script server.ts on a Windows machine. Which command correctly compiles it for Linux?

hard

A. deno compile --output server-linux --platform linux server.ts

B. deno compile --output server-linux --os linux server.ts

C. deno compile --output server-linux --target x86_64-unknown-linux-gnu server.ts

D. deno compile --output server-linux --target linux-x64 server.ts

Solution

1. Step 1: Understand cross-compilation with deno compile

   You must specify the target triple for the desired OS and architecture using --target.

2. Step 2: Identify the correct target triple for Linux x64

   x86_64-unknown-linux-gnu is the standard target triple for 64-bit Linux.

3. Step 3: Check other options for invalid flags or values

   --platform and --os are not valid flags; linux-x64 is not a recognized target triple.

4. Final Answer:

   deno compile --output server-linux --target x86_64-unknown-linux-gnu server.ts -> Option C

5. Quick Check:

   Cross-compile uses --target with correct triple [OK]

Hint: Use --target with OS-arch triple for cross-compiling [OK]

Common Mistakes:

• Using invalid flags like --platform or --os
• Wrong target triple format
• Assuming compile auto-detects target OS