Don't create folder that already exists

[elharo]

fix #1646

[chanseokoh]

The javadoc of createFolders says you can pass null for the monitor.

[chanseokoh]

Not a big deal, but this doesn't need to be a field, at least for now.

[codecov-io]

Codecov Report

Merging #1649 into master will increase coverage by 0.22%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master    #1649      +/-   ##
============================================
+ Coverage     71.88%   72.11%   +0.22%     
- Complexity     1400     1435      +35     
============================================
  Files           247      248       +1     
  Lines          9237     9381     +144     
  Branches        794      820      +26     
============================================
+ Hits           6640     6765     +125     
- Misses         2266     2279      +13     
- Partials        331      337       +6

Impacted Files	Coverage Δ	Complexity Δ
...gle/cloud/tools/eclipse/util/io/ResourceUtils.java	75% <ø> (-16.67%)	2 <0> (-1)
...appengine/facets/StandardFacetInstallDelegate.java	93.75% <100%> (+0.56%)	6 <3> (+1)	⬆️
...tools/eclipse/appengine/facets/WebProjectUtil.java	73.33% <100%> (ø)	5 <0> (ø)	⬇️
...gine/deploy/ui/StandardDeployPreferencesPanel.java	81.42% <0%> (-0.86%)	32% <0%> (+10%)
...ppengine/flex/deploy/FlexDeployCommandHandler.java	0% <0%> (ø)	0% <0%> (?)
...ppengine/deploy/ui/FlexDeployPreferencesPanel.java	51.76% <0%> (+0.57%)	8% <0%> (+1%)	⬆️
.../cloud/tools/eclipse/login/ui/AccountSelector.java	93.2% <0%> (+0.66%)	36% <0%> (+14%)	⬆️
.../src/com/google/cloud/tools/eclipse/util/Xslt.java	77.77% <0%> (+0.85%)	3% <0%> (ø)	⬇️
...loud/tools/eclipse/swtbot/SwtBotTreeUtilities.java	18.75% <0%> (+1.04%)	5% <0%> (ø)	⬇️
... and 7 more

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[chanseokoh]

The new test seems flaky. The error looks interesting to me.

testCreateConfigFiles(com.google.cloud.tools.eclipse.appengine.facets.StandardFacetInstallDelegateTest)  Time elapsed: 2.094 sec  <<< ERROR!
org.eclipse.core.internal.resources.ResourceException: Resource is out of sync with the file system: '/test0.10732607351401313/src/main/webapp/WEB-INF/appengine-web.xml'.
	at org.eclipse.core.internal.localstore.FileSystemResourceManager.read(FileSystemResourceManager.java:830)
	at org.eclipse.core.internal.resources.File.getContents(File.java:269)
	at org.eclipse.core.internal.resources.File.getContents(File.java:260)
	at com.google.cloud.tools.eclipse.appengine.facets.StandardFacetInstallDelegateTest.testCreateConfigFiles(StandardFacetInstallDelegateTest.java:61)

Looks like we need to investigate the flaky test failure.

[elharo]

I think this is what's going on:

https://wiki.eclipse.org/FAQ_When_should_I_use_refreshLocal%3F

[chanseokoh]

That seems like the case! We actually have some other places we modify files without using Eclipse API (e.g., XSLT transformation in App Engine Standard project conversion and XML validation), so we need to revisit them too.

[elharo]

Maybe we should look into createConfigFiles to see if it needs to call refereshLocal

[elharo]

FYI, I've rerun this three times now and have seen any flakiness since the latest changes.

[chanseokoh]

Maybe we should look into createConfigFiles to see if it needs to call refereshLocal

I'm also thinking if refreshLocal shouldn't be the right way.

[elharo]

Ping. This needs an approval.