Non-existent (invisible?) static analysis block shows 75% code coverage

[linusjf]

From StackOverflow Question

Steps to reproduce

• JaCoCo version: 0.85
• Operating system: Linux
• Tool integration: Maven
• Complete executable reproducer: https://github.com/Fernal73/DSAlgos
• Steps: Run Jacoco on project and check report for BrickSortParallel class.

Expected behaviour

No static block or incomplete coverage for class expected.

Actual behaviour

50% code coverage displayed for static block (not visible).

[marchof]

Your code uses the assert keyword which results in a static initializer:

static {};
  descriptor: ()V
  flags: (0x0008) ACC_STATIC
  Code:
    stack=1, locals=0, args_size=0
       0: ldc           #72                 // class ds/BrickSortParallel
       2: invokevirtual #73                 // Method java/lang/Class.desiredAssertionStatus:()Z
       5: ifne          12
       8: iconst_1
       9: goto          13
      12: iconst_0
      13: putstatic     #31                 // Field $assertionsDisabled:Z
      16: return
    LineNumberTable:
      line 19: 0
    StackMapTable: number_of_entries = 2
      frame_type = 12 /* same */
      frame_type = 64 /* same_locals_1_stack_item */
        stack = [ int ]

This is a know limitation. The workaround is to not use assert.

[marchof]

Duplicate #613.

[linusjf]

I've flagged the method that uses assert with a @Generated annotation. Doesn't that filter that out? I'm aware that assert is not filtered out by Jacoco. It's on the things-to-do list. So the @Generated annotation doesn't help?

[linusjf]

Another question wrt to the Google Group:
https://groups.google.com/g/jacoco/c/k7yvGHGExvg

I can't seem to create a new thread online. Is the only way to do it is email the group, instead?

[marchof]

@Fernal73 The method as such will be excluded due to the @Generated annotation. But the Java compiler creates additional infrastructure for assertions in the static initializer.

[marchof]

@Fernal73 Does the "New conversation" button nut work for you?

[linusjf]

No.

[linusjf]

@Fernal73 The method as such will be excluded due to the @Generated annotation. But the Java compiler creates additional infrastructure for assertions in the static initializer.

Thanks for clearing that up. I wasn't aware that it's a static initialiser. Evidently, I'm not familiar with java byte code. I had removed the assert statement earlier but then felt it's a good idea to push it into a @Generated method. I guess I didn't notice that the code coverage earlier was incomplete because of the static block it generates. It's a shame , really, since assertions can be useful without having to use an external API.

[marchof]

@Fernal73 Not true, JDK nowadays provides APIs for this, for example java.util.Objects.nonNull()

[linusjf]

@Fernal73 Does the "New conversation" button nut work for you?

Why nut? Is the email group only for the crazies over there?

[linusjf]

@Fernal73 Not true, JDK nowadays provides APIs for this, for example java.util.Objects.nonNull()

I discovered this excellent explanation on StackOverflow.