Improve writing changes to ide.properties

[hohwille]

In case we are changing the value of a property and saving the changes back to disc, I want to have that the order of the lines in the ide.properties file remains stable so that only the new value is changed in the line where the property was declared before.

Assuming we have this ide.properties file with some legacy history:

#here we define the maven version for both the old and the new release to avoid incompatiblities...
MVN_VERSION=3.9.4
MAVEN_VERSION=${MVN_VERSION}
#here we define to use commercial ultimate edition for Intellij as all team members have a license...
INTELLIJ_EDITION=ultimate
INTELLIJ_EDITION_TYPE=u

Now if we run ide version-set mvn 3.9.5 (see #79) we should get:

#here we define the maven version for both the old and the new release to avoid incompatiblities...
MVN_VERSION=3.9.5
MAVEN_VERSION=${MVN_VERSION}
#here we define to use commercial ultimate edition for Intellij as all team members have a license...
INTELLIJ_EDITION=ultimate
INTELLIJ_EDITION_TYPE=u

So the following would be undesired:

#here we define the maven version for both the old and the new release to avoid incompatiblities...
MAVEN_VERSION=${MVN_VERSION}
#here we define to use commercial ultimate edition for Intellij as all team members have a license...
INTELLIJ_EDITION=ultimate
INTELLIJ_EDITION_TYPE=u
MVN_VERSION=3.9.5

Even more wrong would be:

#here we define the maven version for both the old and the new release to avoid incompatiblities...
MVN_VERSION=3.9.4
MAVEN_VERSION=${MVN_VERSION}
#here we define to use commercial ultimate edition for Intellij as all team members have a license...
INTELLIJ_EDITION=ultimate
INTELLIJ_EDITION_TYPE=u
MVN_VERSION=3.9.5

[MattesMrzik]

I have looked at the code and also tried some value changes of properties and saved the changes back to disc. I set some arbitrary helm versions.
ide set-version helm 1
then after some additional manual changes the file settings/ide.properties looked like:

...
HELM_VERSION=1
a=1
b=2
c=3

Then I ran ide set-version helm 1.1 and the file then looked just as desired:

...
HELM_VERSION=1.1
a=1
b=2
c=3

[MattesMrzik]

EnvironmentVariablesPropertiesFile.set() can create new properties. It can also set new values for existing ones or change the "export" flag. Possibly a bug: the "export" flag is only updated if the value changes as well.