* ext/coverage/coverage.c: Add Coverage.peek_result. Allows you to

capture coverage information without stopping the coverage tool.
  [ruby-core:67940] [Feature #10816]

* test/coverage/test_coverage.rb: test for change.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49589 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,11 @@
+Sat Feb 14 00:49:37 2015  Aaron Patterson <aaron@tenderlovemaking.com>
+
+	* ext/coverage/coverage.c: Add Coverage.peek_result.  Allows you to
+	  capture coverage information without stopping the coverage tool.
+	  [ruby-core:67940] [Feature #10816]
+
+	* test/coverage/test_coverage.rb: test for change.
+
 Fri Feb 13 21:52:05 2015  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* string.c (str_discard): does not free for STR_NOFREE string.

NEWS

@@ -44,6 +44,10 @@ with all sufficient information, see the ChangeLog file.
  * Base64.urlsafe_decode64: now it accepts not only correctly-padded
    input but also unpadded input.
 
+* ext/coverage/coverage.c
+  * Coverage.peek_result: new method to allow coverage to be captured without
+    stopping the coverage tool.
+
 === Built-in global variables compatibility issues
 
 === C API updates

ext/coverage/coverage.c

@@ -33,18 +33,44 @@ rb_coverage_start(VALUE klass)
 }
 
 static int
-coverage_result_i(st_data_t key, st_data_t val, st_data_t h)
+coverage_clear_result_i(st_data_t key, st_data_t val, st_data_t h)
+{
+    VALUE coverage = (VALUE)val;
+    rb_ary_clear((VALUE)val);
+    return ST_CONTINUE;
+}
+
+static int
+coverage_peek_result_i(st_data_t key, st_data_t val, st_data_t h)
 {
     VALUE path = (VALUE)key;
     VALUE coverage = (VALUE)val;
     VALUE coverages = (VALUE)h;
     coverage = rb_ary_dup(coverage);
-    rb_ary_clear((VALUE)val);
     rb_ary_freeze(coverage);
     rb_hash_aset(coverages, path, coverage);
     return ST_CONTINUE;
 }
 
+/*
+ *  call-seq:
+ *     Coverage.peek_result  => hash
+ *
+ * Returns a hash that contains filename as key and coverage array as value.
+ */
+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);
+    rb_hash_freeze(ncoverages);
+    return ncoverages;
+}
+
 /*
  *  call-seq:
  *     Coverage.result  => hash
@@ -55,13 +81,9 @@ coverage_result_i(st_data_t key, st_data_t val, st_data_t h)
 static VALUE
 rb_coverage_result(VALUE klass)
 {
+    VALUE ncoverages = rb_coverage_peek_result(klass);
     VALUE coverages = rb_get_coverages();
-    VALUE ncoverages = rb_hash_new();
+    st_foreach(RHASH_TBL(coverages), coverage_clear_result_i, ncoverages);
-    if (!RTEST(coverages)) {
-	rb_raise(rb_eRuntimeError, "coverage measurement is not enabled");
-    }
-    st_foreach(RHASH_TBL(coverages), coverage_result_i, ncoverages);
-    rb_hash_freeze(ncoverages);
     rb_reset_coverages();
     return ncoverages;
 }
@@ -105,5 +127,6 @@ Init_coverage(void)
     VALUE rb_mCoverage = rb_define_module("Coverage");
     rb_define_module_function(rb_mCoverage, "start", rb_coverage_start, 0);
     rb_define_module_function(rb_mCoverage, "result", rb_coverage_result, 0);
+    rb_define_module_function(rb_mCoverage, "peek_result", rb_coverage_peek_result, 0);
     rb_gc_register_address(&rb_coverages);
 }

test/coverage/test_coverage.rb

@@ -16,6 +16,32 @@ class TestCoverage < Test::Unit::TestCase
     end
   end
 
+  def test_coverage_snapshot
+    loaded_features = $".dup
+
+    Dir.mktmpdir {|tmp|
+      Dir.chdir(tmp) {
+        File.open("test.rb", "w") do |f|
+          f.puts <<-EOS
+            def coverage_test_method
+              :ok
+            end
+          EOS
+        end
+
+        Coverage.start
+        require tmp + '/test.rb'
+        cov = Coverage.peek_result[tmp + '/test.rb']
+        coverage_test_method
+        cov2 = Coverage.peek_result[tmp + '/test.rb']
+        assert_equal cov[1] + 1, cov2[1]
+        assert_equal cov2, Coverage.result[tmp + '/test.rb']
+      }
+    }
+  ensure
+    $".replace loaded_features
+  end
+
   def test_restarting_coverage
     loaded_features = $".dup