LineLength check documentation incorrectly shows how to work with tabWidth property

[danielrcollins1]

Sad documentation defect

https://checkstyle.org/config_sizes.html#LineLength_Notes

To specify a different number of spaces, the user can set TreeWalker property tabWidth which applies to all Checks, including LineLength; or can set property tabWidth for LineLength alone.

We need to change Treewalker to Checker.

Line to change

checkstyle/src/xdocs/config_sizes.xml

Line 606 in fc2bdfe

<a href="config.html#TreeWalker"><code>TreeWalker</code></a> property

---

I have read check documentation: https://checkstyle.org/config_xxxxxx.html#NameOfAffectedCheck
I have downloaded the latest checkstyle from: https://checkstyle.org/cmdline.html#Download_and_Run
I have executed the cli and showed it below, as cli describes the problem better than 1,000 words

D:\Dwnl\CheckStyle\BugReports\BadTabWidth>type Config.xml
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
    "https://checkstyle.org/dtds/configuration_1_2.dtd">

<module name="Checker">
   <module name="LineLength"/>
   <module name="TreeWalker">
      <property name="tabWidth" value="3" />
   </module>
</module>

D:\Dwnl\CheckStyle\BugReports\BadTabWidth>type TestLongLine.java
/*
                1234567890123456789012345678901234567890123456789012345678901234567890
*/

D:\Dwnl\CheckStyle\BugReports\BadTabWidth>java -jar checkstyle-10.9.3-all.jar -c Config.xml TestLongLine.java
Starting audit...
[ERROR] D:\Dwnl\CheckStyle\BugReports\BadTabWidth\TestLongLine.java:2: Line is longer than 80 characters (found 86). [LineLength]
Audit done.
Checkstyle ends with 1 errors.

---

The documentation for LineLength says that it honors the TreeWalker tabWidth property, but it does not seem to do so in practice (https://checkstyle.org/config_sizes.html#LineLength).
The sample code file in its second line has 2 tab characters, followed by 70 digits. The config file has tabWidth set to 3, so this should be counted as 76 total characters, and within the default limit of 80 for LineLength. But instead this is counted as 86 characters (what you get if tabs are counted as the default 8 spaces wide each; 70 + 8 + 8 = 86), and thus triggers the LineLength error.
I've also tried setting the tabWidth property within the LineLenth module (as documentation says should work), but that has the same result.

---

Config.xml.txt
TestLongLine.java.txt

[romani]

attention that LineLength is not a child of TreeWalker to reuse or be affected by its property.

   <module name="LineLength"/>
   <module name="TreeWalker">
      <property name="tabWidth" value="3" />
   </module>

https://checkstyle.org/config.html#Checker has property tabWidth , use it.

[danielrcollins1]

Okay, thanks. I guess that must be fairly new?
Documentation linked above still says, "the user can set TreeWalker property tabWidth which applies to all Checks, including LineLength"
Additionally, I got that snippet from the default config file included with the jGRASP IDE install (https://www.jgrasp.org/).

[romani]

Sad documentation defect

https://checkstyle.org/config_sizes.html#LineLength_Notes

To specify a different number of spaces, the user can set TreeWalker property tabWidth which applies to all Checks, including LineLength; or can set property tabWidth for LineLength alone.

We need to change Treewalker to Checker.

[romani]

@danielrcollins1, do you have time to send Pull Request to fix it ?
I put in issue description where to fix it.

[PavanKumarCB]

Hey i would like to take up this issue.
Do you assign the issues or am i free to pick them and raise PR?

[romani]

no assignments, just do comment "I am on it" and start working on any issue that is approved.

[ghost]

i am on it.

[Andromeda227799]

I am on it

[romani]

Fix is merged