Improve lambda method discovery Fixes: #477

[gayanper]

The issue seems to be when resolving lambda method for reactive operators, the binding resolver is not the default binding resolvers which actually resolves the lambda method.

It seems. the AST construction effects which binding resolver is used at runtime in the node. Therefore switched to the using cache AST when available which seems to resolved the issue. Will do some more testing.

[testforstephen]

java-debug/com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/JdtSourceLookUpProvider.java

Lines 266 to 280 in 31cc033

	parser.setSource(source.toCharArray());
	/**
	* See the java doc for { @link ASTParser#setResolveBindings(boolean) }.
	* Binding information is obtained from the Java model. This means that the
	* compilation unit must be located relative to the Java model.
	* This happens automatically when the source code comes from either
	* setSource(ICompilationUnit) or setSource(IClassFile).
	* When source is supplied by setSource(char[]), the location must be
	* established explicitly
	* by setting an environment using setProject(IJavaProject) or
	* setEnvironment(String [], String [], String [], boolean)
	* and a unit name setUnitName(String).
	*/
	parser.setEnvironment(new String[0], new String[0], null, true);
	parser.setUnitName(Paths.get(filePath).getFileName().toString());

When parsing the AST for the lambda, we just passed a char array without the context Java model or project, that's why the binding information is not resolved correctly.

Your workaround seems OK. Another way to fix this is to find the Java project that the current file belongs to and set the parser to use that project for binding resolver.

[gayanper]

@testforstephen WDYT about the latest change ?

[gayanper]

@testforstephen anything pending for approval and merge ?

[testforstephen]

this PR is on the list for May sprint.

[testforstephen]

java-debug/com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/JdtSourceLookUpProvider.java

Lines 266 to 280 in 31cc033

	parser.setSource(source.toCharArray());
	/**
	* See the java doc for { @link ASTParser#setResolveBindings(boolean) }.
	* Binding information is obtained from the Java model. This means that the
	* compilation unit must be located relative to the Java model.
	* This happens automatically when the source code comes from either
	* setSource(ICompilationUnit) or setSource(IClassFile).
	* When source is supplied by setSource(char[]), the location must be
	* established explicitly
	* by setting an environment using setProject(IJavaProject) or
	* setEnvironment(String [], String [], String [], boolean)
	* and a unit name setUnitName(String).
	*/
	parser.setEnvironment(new String[0], new String[0], null, true);
	parser.setUnitName(Paths.get(filePath).getFileName().toString());

When parsing the AST for the lambda, we just passed a char array without the context Java model or project, that's why the binding information is not resolved correctly.

A simpler fix is to use the parent Java project as the environment. This works for the case in issue #477.

            IFile resource = (IFile) JDTUtils.findResource(JDTUtils.toURI(uri), ResourcesPlugin.getWorkspace().getRoot()::findFilesForLocationURI);
            if (resource != null && JdtUtils.isJavaProject(resource.getProject())) {
                parser.setProject(JavaCore.create(resource.getProject()));
            } else {
                parser.setEnvironment(new String[0], new String[0], null, true);
            }

[gayanper]

java-debug/com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/JdtSourceLookUpProvider.java

Lines 266 to 280 in 31cc033

	parser.setSource(source.toCharArray());
	/**
	* See the java doc for { @link ASTParser#setResolveBindings(boolean) }.
	* Binding information is obtained from the Java model. This means that the
	* compilation unit must be located relative to the Java model.
	* This happens automatically when the source code comes from either
	* setSource(ICompilationUnit) or setSource(IClassFile).
	* When source is supplied by setSource(char[]), the location must be
	* established explicitly
	* by setting an environment using setProject(IJavaProject) or
	* setEnvironment(String [], String [], String [], boolean)
	* and a unit name setUnitName(String).
	*/
	parser.setEnvironment(new String[0], new String[0], null, true);
	parser.setUnitName(Paths.get(filePath).getFileName().toString());

When parsing the AST for the lambda, we just passed a char array without the context Java model or project, that's why the binding information is not resolved correctly.

A simpler fix is to use the parent Java project as the environment. This works for the case in issue #477.

            IFile resource = (IFile) JDTUtils.findResource(JDTUtils.toURI(uri), ResourcesPlugin.getWorkspace().getRoot()::findFilesForLocationURI);
            if (resource != null && JdtUtils.isJavaProject(resource.getProject())) {
                parser.setProject(JavaCore.create(resource.getProject()));
            } else {
                parser.setEnvironment(new String[0], new String[0], null, true);
            }

This is a good suggestion, I change the code now.

[testforstephen]

LGTM. Thanks for contribution.