Question

I want to get code coverage when running unit tests.
I run ant coverage using standard android build.xml for tests.

Tests run well. The last strings from ant coverage are

Tests run: 59,  Failures: 1,  Errors: 4

Generated code coverage data to /data/data/my.package/files/coverage.ec

But the coverage.ec file is only 37 bytes long and is almost empty.

Running emma report on it tells

no collected coverage data found in any of the data files [all reports will be empty]

and generates beautiful report with ZEROES in every field of it.

I suppose that emma should generate a bigger coverage.ec.

What am I doing wrong?

— update —

Did some deep digging. It seems that most of things are well except coverage result generation.

1) It compiles everything saying

[javac] /blabla/android-sdk-linux_x86/tools/ant/main_rules.xml:384: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
[javac] Compiling 88 source files to /blabla/project/tests/instrumented/classes
[javac] Note: Some input files use unchecked or unsafe operations.
[javac] Note: Recompile with -Xlint:unchecked for details.

2) It is doing <instr> with mode="overwrite" for the project that is under test. The path is ok.

-emma-instrument:
[echo] Instrumenting classes from /blabla/project/tests/instrumented/classes…

As a result, there is a *.em file with metadata for 98 classes.

3) Some standard android conversion to dex, package to unaligned, zip align. Result is /blabla/project/tests/instrumented/project-debug.apk.

4) Installing this project-debug.apk onto emulator.

5) Compiling the tests project.
compile:
[javac] /blabla/android-sdk/android-sdk-linux_x86/tools/ant/main_rules.xml:384: warning: ‘includeantruntime’ was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
[javac] Compiling 110 source files to /blabla/project/tests/bin/classes

Source files include all the previous files plus tests (110 = 88 + tests), as stated in build.properties (multiple source.dir separated by “;”).

6) Resources, Dex, signing, zip align… Result is projectTest-debug.apk

7) Installing projectTest-debug.apk onto emulator.

8) Running tests through am where “coverage on” specified. It tells that

[exec] Generated code coverage data to /data/data/blabla.project/files/coverage.ec

9) This coverage.ec contains no relevant data. It is 37 bytes long. Report on it tells that

processing input file [/home/ubuntu/projects/ppf2/workspace/PPF2/tests/coverage.ec] ...
loaded 0 coverage data entries
...
no collected coverage data found in any of the data files [all reports will be empty]

Everything seems good for me except the last step.

Answer 1

Finally, after many hours of fighting, question resolved.
Resolution is very simple and unexpectable.

In build.properties of the TEST project I had something like:

tested.project.dir=..
env.WORKSPACE= /bla/bla
source.dir=${env.WORKSPACE}/first/src;${env.WORKSPACE}/second/src;${env.WORKSPACE}/andsoon/src;

But! I should NOT specify source.dir here! Specifying tested.project.dir is enough to compile test project successfully.

Moreover, if I specify source.dir in TEST project like this – tests run well but emma reports zero coverage, just as stated in question.