You probably know:

• git diff shows unstaged changes.
• git diff --cached shows staged changes.

But how do you see all changes in one go? Just use:

git diff HEAD

Here's the breakdown:

• git diff compares the working directory to the staged index. If nothing is staged, it's the same as git diff HEAD.
• git diff --cached compares the staged index to HEAD. It's a shortcut for git diff --cached HEAD.
• git diff HEAD (or git diff <commit/branch/tag>) compares your current working directory with the specified commit.

Writing commit message could be time-consuming if you want a good summrize. ChatGPT just released their cheapest but still powerful model gpt-4o-mini, we can use it to save our time and keep the commit message accurate.

Attention

I refine the following script time by time and keep the latest version on github. Click here to see the latest version!

You need to put your API KEY in environment variable OPENAI_API_KEY before running this script. You need to run git add first before running this ci script. If you don't want to bother adding first, change git diff --cached -w -b to git diff -w -b and add -a option in the commit command (the last line of the script)

#!/bin/bash

# Get git changes
changes=$(git diff --cached -w -b)

# Exit if no changes
if [ -z "$changes" ]; then
  echo "No changes to commit."
  exit 0
fi

# Set prompt template
prompt_template=$(cat <<-END
You are skilled at writing git commit messages and follow the conventional commits specification:

    refactor: for refactoring
    fix: for bug fixes
    minor: for minor changes
    ...

You will be given the changes from a 'git diff -w -b HEAD' command.
Please summarize all meaningful changes into one commit message, no more than 100 characters.
Respond only with the commit message. Do not mention unchanged aspects. Do not put doube quote in the message. Do not escape underscore characters.
DO REVISE THE MESSAGE THREE TIMES before sending it out. And again: no more than 100 characters!!!
Here are the changes:

END
)

prompt_template+="$changes"

# Build JSON request body using jq
request_body=$(jq -n --arg model "gpt-4o-mini-2024-07-18" --arg prompt "$prompt_template" \
  '{model: $model, messages: [{role:"system",content:"You are a programmer"},{role: "user", content: $prompt}], max_tokens: 32768, seed: 45, temperature: 0}')

# Use curl to request the OpenAI API to generate a commit message
response=$(curl -s --request POST \
  --url https://api.openai.com/v1/chat/completions \
  --header "Authorization: Bearer $OPENAI_API_KEY" \
  --header "Content-Type: application/json" \
  --data "$request_body")

# Extract commit message from the response
commit_message=$(echo "$response" | jq -r '.choices[0].message.content')

# Exit if the commit message is empty
if [ -z "$commit_message" ] || [ "$commit_message" == "null" ]; then
  echo 'failed to generate a commit message:'
  echo $response
  exit 1
fi

# Commit changes
git commit -m "$commit_message"
```bash
**2024-07-24 update**
## Free alternative provided by Groq

If you don't want to pay for the ChatGPT API, you can opt for the free alternative provided by [Groq](https://groq.com). To get started, simply sign up for a Groq account using Google Login. Once you've created your account, you can generate an API key by following this link: <https://console.groq.com/keys>. Finally, make a minor modification to your script, as outlined below.

Build JSON request body using jq

#request_body=$(jq -n _{arg model "gpt-4o-mini-2024-07-18"} arg prompt "$prompt_template" \

'{model: $model, messages: [{role:"system",content:"You are a programmer"},{role: "user", content: $prompt}], max_tokens: 50, seed: 45, temperature: 0}')

#response=$(curl -s --request POST \

--url https://api.openai.com/v1/chat/completions \

--header "Authorization: Bearer $OPENAI_API_KEY" \

--header "Content-Type: application/json" \

--data "$request_body")

request_body=$(jq -n _{arg model "mixtral-8x7b-32768"} arg prompt "$prompt_template"
'{model: $model, messages: [{role:"system",content:"You are a programmer"},{role: "user", content: $prompt}], max_tokens: 32768, stream: false, temperature: 0, top_p: 1, stop: null}')

Use curl to request the OpenAI API to generate a commit message

response=$(curl -s _{request POST}
url https://api.groq.com/openai/v1/chat/completions
_{header "Authorization: Bearer $GROQ_API_KEY"}
header "Content-Type: application/json"
--data "$request_body")

The Dart ... spread operator is a powerful feature that allows you to insert multiple elements from a collection into another collection. This is particularly useful when building Flutter widget trees, as it can make your code more concise and readable.

What is the Spread Operator ...?

The ... operator is used to expand elements of a collection and add them to another collection. For example:

List<int> list1 = [1, 2, 3];
List<int> list2 = [0, ...list1, 4];
print(list2); // Output: [0, 1, 2, 3, 4]

Using the Spread Operator in Flutter Widgets

In Flutter, you can use the ... operator to conditionally add multiple widgets to a widget list, making the code cleaner and more maintainable.

Without the Spread Operator

If you don't use the ... operator, you might end up writing repetitive conditional checks like this:

AppBar(
  title: const Text('Note Details'),
  actions: [
    if (widget.note.userId == UserSession().id)
      IconButton(
        icon: const Icon(Icons.edit),
        onPressed: _enterEditingMode,
      ),
    if (widget.note.userId == UserSession().id)
      IconButton(
        icon: const Icon(Icons.delete),
        onPressed: () async {
          await DialogService.showConfirmDialog(
            context,
            title: 'Delete note',
            text: 'Each note is a story, are you sure you want to delete it?',
            yesCallback: () => _controller.deleteNote(context, widget.note.id),
          );
        },
      ),
  ],
)

This approach involves duplicating the condition check for each widget, making the code verbose and harder to maintain.

With the Spread Operator

Using the ... spread operator, you can simplify the code by grouping the widgets under a single conditional check:

AppBar(
  title: const Text('Note Details'),
  actions: [
    if (widget.note.userId == UserSession().id) ...[
      IconButton(
        icon: const Icon(Icons.edit),
        onPressed: _enterEditingMode,
      ),
      IconButton(
        icon: const Icon(Icons.delete),
        onPressed: () async {
          await DialogService.showConfirmDialog(
            context,
            title: 'Delete note',
            text: 'Each note is a story, are you sure you want to delete it?',
            yesCallback: () => _controller.deleteNote(context, widget.note.id),
          );
        },
      ),
    ],
  ],
)

This method is more concise and only requires a single condition check, reducing redundancy and improving readability.

Benefits of Using the Spread Operator

1. Reduces Code Duplication: The spread operator allows you to write less code by removing the need for multiple conditional checks.
2. Improves Readability and Maintainability: With fewer lines of code and clearer structure, your code is easier to read and maintain.
3. Simplifies Conditional Addition of Multiple Elements: When you need to add multiple elements based on a condition, the spread operator provides a clean and efficient way to do so.