gitlint/docs/rules.md

# Overview

The table below shows an overview of all gitlint's built-in rules, with more specific details further down the page.

Gitlint also has [community **contrib**uted rules](contrib_rules.md) which are not listed here as they're disabled by default.

In addition, you can also [write your own user-defined rule](user_defined_rules.md) in case you don't find
what you're looking for.


| ID  | Name                        | gitlint version | Description                                                                                 |
| --- | --------------------------- | --------------- | ------------------------------------------------------------------------------------------- |
| T1  | title-max-length            | >= 0.1.0        | Title length must be <= 72 chars.                                                        |
| T2  | title-trailing-whitespace   | >= 0.1.0        | Title cannot have trailing whitespace (space or tab)                                        |
| T3  | title-trailing-punctuation  | >= 0.1.0        | Title cannot have trailing punctuation (?:!.,;)                                             |
| T4  | title-hard-tab              | >= 0.1.0        | Title cannot contain hard tab characters (\t)                                               |
| T5  | title-must-not-contain-word | >= 0.1.0        | Title cannot contain certain words (default: "WIP")                                         |
| T6  | title-leading-whitespace    | >= 0.4.0        | Title cannot have leading whitespace (space or tab)                                         |
| T7  | title-match-regex           | >= 0.5.0        | Title must match a given regex (default: None)                                              |
| T8  | title-min-length            | >= 0.14.0       | Title length must be >= 5 chars.                                                         |
| B1  | body-max-line-length        | >= 0.1.0        | Lines in the body must be <= 80 chars                                                    |
| B2  | body-trailing-whitespace    | >= 0.1.0        | Body cannot have trailing whitespace (space or tab)                                         |
| B3  | body-hard-tab               | >= 0.1.0        | Body cannot contain hard tab characters (\t)                                                |
| B4  | body-first-line-empty       | >= 0.1.0        | First line of the body (second line of commit message) must be empty                        |
| B5  | body-min-length             | >= 0.4.0        | Body length must be at least 20 characters                                                  |
| B6  | body-is-missing             | >= 0.4.0        | Body message must be specified                                                              |
| B7  | body-changed-file-mention   | >= 0.4.0        | Body must contain references to certain files if those files are changed in the last commit |
| B8  | body-match-regex            | >= 0.14.0       | Body must match a given regex (default: None)                                               |
| M1  | author-valid-email          | >= 0.9.0        | Author email address must be a valid email address                                          |
| I1  | ignore-by-title             | >= 0.10.0       | Ignore a commit based on matching its title                                                 |
| I2  | ignore-by-body              | >= 0.10.0       | Ignore a commit based on matching its body                                                  |
| I3  | ignore-body-lines           | >= 0.14.0       | Ignore certain lines in a commit body that match a regex                                    |
| I4  | ignore-by-author-name       | >= 0.16.0       | Ignore a commit based on matching its author name                                           |



## T1: title-max-length

| ID  | Name             | gitlint version | Description                          |
| --- | ---------------- | --------------- | ------------------------------------ |
| T1  | title-max-length | >= 0.1          | Title length must be <= 72 chars. |

### Options

| Name        | gitlint version | Default | Description                  |
| ----------- | --------------- | ------- | ---------------------------- |
| line-length | >= 0.2          | 72      | Maximum allowed title length |

### Examples

#### .gitlint

```ini
# Titles should be max 72 chars
[title-max-length]
line-length=72

# It's the 21st century, titles can be 120 chars long
[title-max-length]
line-length=120
```
------------------------------------------------------------------------------------------------------------------------

## T2: title-trailing-whitespace

| ID  | Name                      | gitlint version | Description                                          |
| --- | ------------------------- | --------------- | ---------------------------------------------------- |
| T2  | title-trailing-whitespace | >= 0.1          | Title cannot have trailing whitespace (space or tab) |

------------------------------------------------------------------------------------------------------------------------

## T3: title-trailing-punctuation

| ID  | Name                       | gitlint version | Description                                     |
| --- | -------------------------- | --------------- | ----------------------------------------------- |
| T3  | title-trailing-punctuation | >= 0.1          | Title cannot have trailing punctuation (?:!.,;) |

------------------------------------------------------------------------------------------------------------------------

## T4: title-hard-tab

| ID  | Name           | gitlint version | Description                                   |
| --- | -------------- | --------------- | --------------------------------------------- |
| T4  | title-hard-tab | >= 0.1          | Title cannot contain hard tab characters (\t) |

------------------------------------------------------------------------------------------------------------------------

## T5: title-must-not-contain-word

| ID  | Name                        | gitlint version | Description                                         |
| --- | --------------------------- | --------------- | --------------------------------------------------- |
| T5  | title-must-not-contain-word | >= 0.1          | Title cannot contain certain words (default: "WIP") |

### Options

| Name  | gitlint version | Default | Description                                                                                      |
| ----- | --------------- | ------- | ------------------------------------------------------------------------------------------------ |
| words | >= 0.3          | WIP     | Comma-separated list of words that should not be used in the title. Matching is case insensitive |

### Examples

#### .gitlint

```ini
# Ensure the title doesn't contain swear words
[title-must-not-contain-word]
words=crap,darn,damn
```
------------------------------------------------------------------------------------------------------------------------

## T6: title-leading-whitespace

| ID  | Name                     | gitlint version | Description                                         |
| --- | ------------------------ | --------------- | --------------------------------------------------- |
| T6  | title-leading-whitespace | >= 0.4          | Title cannot have leading whitespace (space or tab) |

------------------------------------------------------------------------------------------------------------------------

## T7: title-match-regex

| ID  | Name              | gitlint version | Description                                  |
| --- | ----------------- | --------------- | -------------------------------------------- |
| T7  | title-match-regex | >= 0.5          | Title must match a given regex (default: .*) |


### Options

| Name  | gitlint version | Default | Description                                                                          |
| ----- | --------------- | ------- | ------------------------------------------------------------------------------------ |
| regex | >= 0.5          | .*      | [Python regex](https://docs.python.org/library/re.html) that the title should match. |

### Examples

#### .gitlint

```ini
# Ensure every title starts with a user-story like US123
[title-match-regex]
regex=^US[1-9][0-9]*
```
------------------------------------------------------------------------------------------------------------------------

## T8: title-min-length ##

| ID  | Name             | gitlint version | Description                         |
| --- | ---------------- | --------------- | ----------------------------------- |
| T8  | title-min-length | >= 0.14.0       | Title length must be >= 5 chars. |


### Options

| Name       | gitlint version | Default | Description                   |
| ---------- | --------------- | ------- | ----------------------------- |
| min-length | >= 0.14.0       | 5       | Minimum required title length |

### Examples

#### .gitlint

```ini
# Titles should be min 3 chars
[title-min-length]
min-length=3
```
------------------------------------------------------------------------------------------------------------------------

## B1: body-max-line-length

| ID  | Name                 | gitlint version | Description                              |
| --- | -------------------- | --------------- | ---------------------------------------- |
| B1  | body-max-line-length | >= 0.1          | Lines in the body must be <= 80 chars |

### Options

| Name        | gitlint version | Default | Description                                            |
| ----------- | --------------- | ------- | ------------------------------------------------------ |
| line-length | >= 0.2          | 80      | Maximum allowed line length in the commit message body |

### Examples

#### .gitlint

```ini
# It's the 21st century, lines can be 120 chars long
[body-max-line-length]
line-length=120

# Your tool prefers 72
[body-max-line-length]
line-length=72
```
------------------------------------------------------------------------------------------------------------------------

## B2: body-trailing-whitespace

| ID  | Name                     | gitlint version | Description                                         |
| --- | ------------------------ | --------------- | --------------------------------------------------- |
| B2  | body-trailing-whitespace | >= 0.1          | Body cannot have trailing whitespace (space or tab) |

------------------------------------------------------------------------------------------------------------------------

## B3: body-hard-tab

| ID  | Name          | gitlint version | Description                                  |
| --- | ------------- | --------------- | -------------------------------------------- |
| B3  | body-hard-tab | >= 0.1          | Body cannot contain hard tab characters (\t) |

------------------------------------------------------------------------------------------------------------------------

## B4: body-first-line-empty

| ID  | Name                  | gitlint version | Description                                                          |
| --- | --------------------- | --------------- | -------------------------------------------------------------------- |
| B4  | body-first-line-empty | >= 0.1          | First line of the body (second line of commit message) must be empty |

------------------------------------------------------------------------------------------------------------------------

## B5: body-min-length

| ID  | Name            | gitlint version | Description                                                                                                  |
| --- | --------------- | --------------- | ------------------------------------------------------------------------------------------------------------ |
| B5  | body-min-length | >= 0.4          | Body length must be at least 20 characters. In versions >= 0.8.0, gitlint will not count newline characters. |

### Options ###

| Name       | gitlint version | Default | Description                                   |
| ---------- | --------------- | ------- | --------------------------------------------- |
| min-length | >= 0.4          | 20      | Minimum number of required characters in body |

### Examples

#### .gitlint

```ini
# You want *something* in every commit body, but doesn't have to be as long as 20 chars.
[body-min-length]
min-length=5

# You want a more elaborate message in every commit body
[body-min-length]
min-length=100
```
------------------------------------------------------------------------------------------------------------------------

## B6: body-is-missing

| ID  | Name            | gitlint version | Description                    |
| --- | --------------- | --------------- | ------------------------------ |
| B6  | body-is-missing | >= 0.4          | Body message must be specified |


### Options

| Name                 | gitlint version | Default | Description                                                                           |
| -------------------- | --------------- | ------- | ------------------------------------------------------------------------------------- |
| ignore-merge-commits | >= 0.4          | true    | Whether this rule should be ignored during merge commits. Allowed values: true,false. |

------------------------------------------------------------------------------------------------------------------------

## B7: body-changed-file-mention

| ID  | Name                      | gitlint version | Description                                                                                 |
| --- | ------------------------- | --------------- | ------------------------------------------------------------------------------------------- |
| B7  | body-changed-file-mention | >= 0.4          | Body must contain references to certain files if those files are changed in the last commit |

### Options

| Name  | gitlint version | Default | Description                                                                                                    |
| ----- | --------------- | ------- | -------------------------------------------------------------------------------------------------------------- |
| files | >= 0.4          | (empty) | Comma-separated list of files that need to an explicit mention in the commit message in case they are changed. |

### Examples

#### .gitlint

```ini
# Prevent that certain sensitive files are committed by mistake by forcing
# users to mention them explicitly if they're deliberately changing them
[body-changed-file-mention]
files=generated.xml,secrets.txt,private-key.pem
```
------------------------------------------------------------------------------------------------------------------------

## B8: body-match-regex

| ID  | Name             | gitlint version | Description                   |
| --- | ---------------- | --------------- | ----------------------------- |
| B8  | body-match-regex | >= 0.14         | Body must match a given regex |

### Options

| Name  | gitlint version | Default | Description                                                                         |
| ----- | --------------- | ------- | ----------------------------------------------------------------------------------- |
| regex | >= 0.14         | None    | [Python regex](https://docs.python.org/library/re.html) that the body should match. |

### Examples

#### .gitlint

```ini
# Ensure the body ends with Reviewed-By: <some value>
[body-match-regex]
regex=Reviewed-By:(.*)$

# Ensure body contains the word "Foo" somewhere
[body-match-regex]
regex=(*.)Foo(.*)
```
------------------------------------------------------------------------------------------------------------------------

## M1: author-valid-email

| ID  | Name               | gitlint version | Description                                        |
| --- | ------------------ | --------------- | -------------------------------------------------- |
| M1  | author-valid-email | >= 0.8.3        | Author email address must be a valid email address |

!!! note
    Email addresses are [notoriously hard to validate and the official email valid spec is often too loose for any real world application](http://stackoverflow.com/a/201378/381010).
    Gitlint by default takes a pragmatic approach and requires users to enter email addresses that contain a name, domain and tld and has no spaces.



### Options

| Name  | gitlint version | Default                 | Description                                                                                                |
| ----- | --------------- | ----------------------- | ---------------------------------------------------------------------------------------------------------- |
| regex | >= 0.9.0        | `[^@ ]+@[^@ ]+\.[^@ ]+` | [Python regex](https://docs.python.org/library/re.html) the commit author email address is matched against |


### Examples

#### .gitlint

```ini
# Only allow email addresses from a foo.com domain
[author-valid-email]
regex=[^@]+@foo.com
```
------------------------------------------------------------------------------------------------------------------------

## I1: ignore-by-title

| ID  | Name            | gitlint version | Description                                  |
| --- | --------------- | --------------- | -------------------------------------------- |
| I1  | ignore-by-title | >= 0.10.0       | Ignore a commit based on matching its title. |


### Options

| Name   | gitlint version | Default | Description                                                                                                                  |
| ------ | --------------- | ------- | ---------------------------------------------------------------------------------------------------------------------------- |
| regex  | >= 0.10.0       | None    | [Python regex](https://docs.python.org/library/re.html) to match against commit title. On match, the commit will be ignored. |
| ignore | >= 0.10.0       | all     | Comma-separated list of rule names or ids to ignore when this rule is matched.                                               |

### Examples

#### .gitlint

```ini
# Match commit titles starting with Release
# For those commits, ignore title-max-length and body-min-length rules
[ignore-by-title]
regex=^Release(.*)
ignore=title-max-length,body-min-length
# ignore all rules by setting ignore to 'all'
# ignore=all
```
------------------------------------------------------------------------------------------------------------------------

## I2: ignore-by-body

| ID  | Name           | gitlint version | Description                                 |
| --- | -------------- | --------------- | ------------------------------------------- |
| I2  | ignore-by-body | >= 0.10.0       | Ignore a commit based on matching its body. |


### Options

| Name   | gitlint version | Default | Description                                                                                                                           |
| ------ | --------------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| regex  | >= 0.10.0       | None    | [Python regex](https://docs.python.org/library/re.html) to match against each line of the body. On match, the commit will be ignored. |
| ignore | >= 0.10.0       | all     | Comma-separated list of rule names or ids to ignore when this rule is matched.                                                        |

### Examples

#### .gitlint

```ini
# Ignore all commits with a commit message body with a line that contains 'release'
[ignore-by-body]
regex=(.*)release(.*)
ignore=all

# For matching commits, only ignore rules T1, body-min-length, B6.
# You can use both names as well as ids to refer to other rules.
[ignore-by-body]
regex=(.*)release(.*)
ignore=T1,body-min-length,B6
```
------------------------------------------------------------------------------------------------------------------------

## I3: ignore-body-lines

| ID  | Name              | gitlint version | Description                                               |
| --- | ----------------- | --------------- | --------------------------------------------------------- |
| I3  | ignore-body-lines | >= 0.14.0       | Ignore certain lines in a commit body that match a regex. |


### Options

| Name  | gitlint version | Default | Description                                                                                                                                                                                 |
| ----- | --------------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| regex | >= 0.14.0       | None    | [Python regex](https://docs.python.org/library/re.html) to match against each line of the body. On match, that line will be ignored by gitlint (the rest of the body will still be linted). |

### Examples

#### .gitlint

```ini
# Ignore all lines that start with 'Co-Authored-By'
[ignore-body-lines]
regex=^Co-Authored-By

# Ignore lines that start with 'Co-Authored-By' or with 'Signed-off-by'
[ignore-body-lines]
regex=(^Co-Authored-By)|(^Signed-off-by)

# Ignore lines that contain 'foobar'
[ignore-body-lines]
regex=(.*)foobar(.*)
```
------------------------------------------------------------------------------------------------------------------------

## I4: ignore-by-author-name

| ID  | Name                  | gitlint version | Description                                        |
| --- | --------------------- | --------------- | -------------------------------------------------- |
| I4  | ignore-by-author-name | >= 0.16.0       | Ignore a commit based on matching its author name. |

### Options

| Name   | gitlint version | Default | Description                                                                                                                            |
| ------ | --------------- | ------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| regex  | >= 0.16.0       | None    | [Python regex](https://docs.python.org/library/re.html) to match against the commit author name. On match, the commit will be ignored. |
| ignore | >= 0.16.0       | all     | Comma-separated list of rule names or ids to ignore when this rule is matched.                                                         |

### Examples

#### .gitlint

```ini
# Ignore all commits authored by dependabot
[ignore-by-author-name]
regex=dependabot

# For commits made by anyone with "[bot]" in their name, ignore
# rules T1, body-min-length and B6
[ignore-by-author-name]
regex=(.*)\[bot\](.*)
ignore=T1,body-min-length,B6
```