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It can’t be emphasized enough how good IEx is. Maybe it’s because it is my first experience with a language like Elixir, but man, it just feels like I’m living

by ketzo 5y ago

It can’t be emphasized enough how good IEx is. Maybe it’s because it is my first experience with a language like Elixir, but man, it just feels like I’m living inside the program while it’s running in a way that an IDE debugger doesn’t. It’s so cool and so powerful.

marcus_cemes 5y ago
I will never forget the first time I started IEx from within a Phoenix project, and found that I had a live shell into the running application, while the Phoenix development server was running and reachable from the browser, all with hot code reloading... No need to create a dummy REST endpoint to try running a function. My mind was blown.
- zorbash 5y ago
  Another thing worth trying, is connecting a Livebook instance (see: https://livebook.dev/ https://livebook.dev/) to a running application. Keep in mind Livebook allows for multiple users to work on the same notebook at once so this can come handy in pair-programming / debugging situations.
arthurcolle 5y ago
:observer.start is awesome too
dnautics 5y ago
It's like you are in bash, except you can run real functions, and your variables aren't stringly typed.
derefr 5y ago
Give a remsh connection to a production cluster, you’ll find IEx really does mean “living inside” the process—you can reach out and add a live trace hook to e.g. a Phoenix Controller function, and then immediately see traces from your live prod users hitting that trace point. Without recompiling or restarting the app—their existing in-memory session state, local in-memory caches, etc. are suddenly exposed to you, without needing to discard any of it via a redeploy/restart and then wait for new user sessions to reproduce the problem. (You can even redefine the module in-place in memory to see how changes affect what you see. Brings a whole new meaning to “hotfix”: you can do hotfixes that don’t even exist on disk!)

by ketzo 5y ago

marcus_cemes 5y ago

I will never forget the first time I started IEx from within a Phoenix project, and found that I had a live shell into the running application, while the Phoenix development server was running and reachable from the browser, all with hot code reloading... No need to create a dummy REST endpoint to try running a function. My mind was blown.

zorbash 5y ago
Another thing worth trying, is connecting a Livebook instance (see: https://livebook.dev/ https://livebook.dev/) to a running application. Keep in mind Livebook allows for multiple users to work on the same notebook at once so this can come handy in pair-programming / debugging situations.

arthurcolle 5y ago

:observer.start is awesome too

dnautics 5y ago

It's like you are in bash, except you can run real functions, and your variables aren't stringly typed.

derefr 5y ago

Give a remsh connection to a production cluster, you’ll find IEx really does mean “living inside” the process—you can reach out and add a live trace hook to e.g. a Phoenix Controller function, and then immediately see traces from your live prod users hitting that trace point. Without recompiling or restarting the app—their existing in-memory session state, local in-memory caches, etc. are suddenly exposed to you, without needing to discard any of it via a redeploy/restart and then wait for new user sessions to reproduce the problem. (You can even redefine the module in-place in memory to see how changes affect what you see. Brings a whole new meaning to “hotfix”: you can do hotfixes that don’t even exist on disk!)