No report for two Classes in the same package with same name

[liangjiancang]

Just as the title says, eclipse will report it.

Environment

• Operating System: Windows 10
• JDK version: 1.8.0_161
• Visual Studio Code version: 1.39.2
• Java extension version: 0.51.0

Steps To Reproduce

// src/test/C1.java
package test;
public class C1 {}
class Same {}

// src/test/C2.java
package test;
public class C2 {}
class Same {}

Current Result

No problem dectected.
Fail to build.

[rgrunber]

$ javac *.java
C2.java:4: error: duplicate class: org.example.Same
class Same {
^
1 error

Eclipse reports The type Same is already defined via ECJ. Not sure why it isn't working in vscode-java.

Update: vscode-java reports it as well but there's still a bug.

C1.java

package org.example;
public class C1 {}

class Same {
}

C2.java

package org.example;
public class C2 {}

class Same {
}

Open up C1.java first, and the language server will begin to load.

I see :

[Trace - 23:21:11] Received notification 'textDocument/publishDiagnostics'.
Params: {
    "uri": "file:///tmp/foo/org/example/C2.java",
    "diagnostics": [
        {
            "range": {
                "start": {
                    "line": 3,
                    "character": 6
                },
                "end": {
                    "line": 3,
                    "character": 10
                }
            },
            "severity": 1,
            "code": "0",
            "source": "Java",
            "message": "The type Same is already defined"
        }
    ]
}

Now open up C1.java

[Trace - 23:23:11] Received notification 'textDocument/publishDiagnostics'.
Params: {
    "uri": "file:///tmp/foo/org/example/C2.java",
    "diagnostics": []
}

The message disappears.

Looking at https://github.com/eclipse-jdt/eclipse.jdt.core/blob/35bf3605e3a1fba5c0864479d04fef13452f9046/org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/CompilationUnitScope.java#L170-L177 it almost seems like didOpen might be losing information about the other parsed files.

[rgrunber]

If one uses Java: Force Java Compilation from the command palette, the error returns. This is starting to look like a case where didOpen on a single file masks some errors that a full compilation would reveal.

It seems like a diagnostic that requires a full build is placed on a single file, so the way to persist it is probably to set the URI for the diagnostic as that of the project.