Line length Open
Theoretically, email addresses can be validated using a regular expression. After all, there are a couple of simple rules, such as the presence of the at (`@`) symbol and an appropriate domain, right? Yes, but there are tons of valid email address that don’t look exactly like that. In fact, there’s a whole standard, [RFC 2822](https://www.rfc-editor.org/rfc/rfc2822#section-3.4.1), that defines what email addresses can look like. Then, there’s the issue of what different mail servers will allow. Gmail, for example, will not allow underscores (`_`) or more than one period (`.`) in a row.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
By now, you should be starting to figure out why I’ve been hesitant to showcase a solution to the problem of email validation. While solutions do exist, the implications of each one must be considered carefully.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
excerpt: Email address validation can be much trickier than it sounds. Here's why and my advice on how to approach this problem.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
Finally, even if you used a regular expression that is compliant with RFC 2822, it wouldn’t be without issues. Understanding how it works or figuring out if it works correctly for each and every case would be pretty difficult. More importantly, though, it could be prone to **regular expression denial of service (ReDoS) attacks**, if implemented incorrectly.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
One of the most frequent code snippet requests I get is about a function that can validate email addresses. While it sounds easy, I’ve been putting off writing about this topic for a while. The reason is that there are **no great solutions to this sort of problem**.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
Additionally, even if you could validate an email address, there’s **no way of knowing if this address is in fact currently in use**. The only way to do so, is to send an email and check the response. This is why most websites and apps nowadays send you a confirmation email in the first place.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.
Line length Open
My suggestion would be to **check for basic structural elements** on the frontend, then **send a confirmation email** from your server to check that the email address is in use. It’s easy to implement and gets the job done. Going back to the original idea, here’s a simple function that checks for the most common syntax errors.- Read upRead up
- Exclude checks
MD013 - Line length
Tags: line_length
Aliases: line-length Parameters: linelength, codeblocks, tables (number; default 80, boolean; default true)
This rule is triggered when there are lines that are longer than the configured line length (default: 80 characters). To fix this, split the line up into multiple lines.
This rule has an exception where there is no whitespace beyond the configured line length. This allows you to still include items such as long URLs without being forced to break them in the middle.
You also have the option to exclude this rule for code blocks and tables. To
do this, set the code_blocks and/or tables parameters to false.
Code blocks are included in this rule by default since it is often a requirement for document readability, and tentatively compatible with code rules. Still, some languages do not lend themselves to short lines.