How to get all packages' code coverage together in Go? - unit-testing

Question

I have a library consisting of several packages. When running tests, I am using '-cover' flag and its showing the coverage information for each package individually.Like follows:
--- PASS: TestSampleTestSuite (0.00s)
PASS
coverage: 28.7% of statements
ok github.com/path/to/package1 13.021s
? github.com/path/to/package2 [no test files]
=== RUN TestAbc
--- PASS: TestAbc (0.43s)
PASS
coverage: 27.7% of statements
Is there any way to get a full coverage overview easily to get good idea about coverage on the whole project?
Update: Here is the go test command I am using
go test ./... -v -short -p 1 -cover

Answer 1

EDIT: Things have changed since I wrote this answer. See the release notes of Go 1.10: https://golang.org/doc/go1.10#test :
The go test -coverpkg flag now interprets its argument as a
comma-separated list of patterns to match against the dependencies of
each test, not as a list of packages to load anew. For example, go
test -coverpkg=all is now a meaningful way to run a test with coverage
enabled for the test package and all its dependencies. Also, the go
test -coverprofile option is now supported when running multiple
tests.
You can now run
go test -v -coverpkg=./... -coverprofile=profile.cov ./...
go tool cover -func profile.cov
Old answer
Here is a bash script extracted from https://github.com/h12w/gosweep :
#!/bin/bash
set -e
echo 'mode: count' > profile.cov
for dir in $(find . -maxdepth 10 -not -path './.git*' -not -path '*/_*' -type d);
do
if ls $dir/*.go &> /dev/null; then
go test -short -covermode=count -coverprofile=$dir/profile.tmp $dir
if [ -f $dir/profile.tmp ]
then
cat $dir/profile.tmp | tail -n +2 >> profile.cov
rm $dir/profile.tmp
fi
fi
done
go tool cover -func profile.cov