Coverage

Module

Coverage provides coverage measurement feature for Ruby. This feature is experimental, so these APIs may be changed in future.

Usage

require “coverage”
do Coverage.start
require or load Ruby source file
Coverage.result will return a hash that contains filename as key and coverage array as value. A coverage array gives, for each line, the number of line execution by the interpreter. A nil value means coverage is disabled for this line (lines like else and end).

Example

[foo.rb]
s = 0
10.times do |x|
  s += x
end

if s == 45
  p :ok
else
  p :ng
end
[EOF]

require "coverage"
Coverage.start
require "foo.rb"
p Coverage.result  #=> {"foo.rb"=>[1, 1, 10, nil, nil, 1, 1, nil, 0, nil]}

Class Methods

Coverage.peek_result => hash

ext/coverage/coverage.c View on GitHub

          
            static VALUE
rb_coverage_peek_result(VALUE klass)
{
    VALUE coverages = rb_get_coverages();
    VALUE ncoverages = rb_hash_new();
    if (!RTEST(coverages)) {
        rb_raise(rb_eRuntimeError, "coverage measurement is not enabled");
    }
    st_foreach(RHASH_TBL(coverages), coverage_peek_result_i, ncoverages);

    if (current_mode & COVERAGE_TARGET_METHODS) {
        rb_objspace_each_objects(method_coverage_i, &ncoverages);
    }

    rb_hash_freeze(ncoverages);
    return ncoverages;
}

Returns a hash that contains filename as key and coverage array as value. This is the same as ‘Coverage.result(stop: false, clear: false)`.

{
  "file.rb" => [1, 2, nil],
  ...
}

Coverage.result(stop: true, clear: true) => hash

ext/coverage/coverage.c View on GitHub

          
            static VALUE
rb_coverage_result(int argc, VALUE *argv, VALUE klass)
{
    VALUE ncoverages;
    VALUE opt;
    int stop = 1, clear = 1;

    rb_scan_args(argc, argv, "01", &opt);

    if (argc == 1) {
        opt = rb_convert_type(opt, T_HASH, "Hash", "to_hash");
        stop = RTEST(rb_hash_lookup(opt, ID2SYM(rb_intern("stop"))));
        clear = RTEST(rb_hash_lookup(opt, ID2SYM(rb_intern("clear"))));
    }

    ncoverages = rb_coverage_peek_result(klass);
    if (stop && !clear) {
        rb_warn("stop implies clear");
        clear = 1;
    }
    if (clear) {
        rb_clear_coverages();
        if (!NIL_P(me2counter)) rb_hash_foreach(me2counter, clear_me2counter_i, Qnil);
    }
    if (stop) {
        rb_reset_coverages();
        me2counter = Qnil;
    }
    return ncoverages;
}

Returns a hash that contains filename as key and coverage array as value. If clear is true, it clears the counters to zero. If stop is true, it disables coverage measurement.

Coverage.running? => bool

ext/coverage/coverage.c View on GitHub

          
            static VALUE
rb_coverage_running(VALUE klass)
{
    VALUE coverages = rb_get_coverages();
    return RTEST(coverages) ? Qtrue : Qfalse;
}

Returns true if coverage stats are currently being collected (after Coverage.start call, but before Coverage.result call)

Coverage.start => nil

ext/coverage/coverage.c View on GitHub

          
            static VALUE
rb_coverage_start(int argc, VALUE *argv, VALUE klass)
{
    VALUE coverages, opt;
    int mode;

    rb_scan_args(argc, argv, "01", &opt);

    if (argc == 0) {
        mode = 0; /* compatible mode */
    }
    else if (opt == ID2SYM(rb_intern("all"))) {
        mode = COVERAGE_TARGET_LINES | COVERAGE_TARGET_BRANCHES | COVERAGE_TARGET_METHODS;
    }
    else {
        mode = 0;
        opt = rb_convert_type(opt, T_HASH, "Hash", "to_hash");

        if (RTEST(rb_hash_lookup(opt, ID2SYM(rb_intern("lines")))))
            mode |= COVERAGE_TARGET_LINES;
        if (RTEST(rb_hash_lookup(opt, ID2SYM(rb_intern("branches")))))
            mode |= COVERAGE_TARGET_BRANCHES;
        if (RTEST(rb_hash_lookup(opt, ID2SYM(rb_intern("methods")))))
            mode |= COVERAGE_TARGET_METHODS;
        if (RTEST(rb_hash_lookup(opt, ID2SYM(rb_intern("oneshot_lines"))))) {
            if (mode & COVERAGE_TARGET_LINES)
                rb_raise(rb_eRuntimeError, "cannot enable lines and oneshot_lines simultaneously");
            mode |= COVERAGE_TARGET_LINES;
            mode |= COVERAGE_TARGET_ONESHOT_LINES;
        }
    }

    if (mode & COVERAGE_TARGET_METHODS) {
        me2counter = rb_hash_new_compare_by_id();
    }
    else {
        me2counter = Qnil;
    }

    coverages = rb_get_coverages();
    if (!RTEST(coverages)) {
        coverages = rb_hash_new();
        rb_obj_hide(coverages);
        current_mode = mode;
        if (mode == 0) mode = COVERAGE_TARGET_LINES;
        rb_set_coverages(coverages, mode, me2counter);
    }
    else if (current_mode != mode) {
        rb_raise(rb_eRuntimeError, "cannot change the measuring target during coverage measurement");
    }
    return Qnil;
}

Enables coverage measurement.