Extract helper for asserting test failures

10 files changed, 494 insertions, 374 deletions

diff --git a/test/50-assert-11-assert.bats b/test/50-assert-11-assert.bats
index 2ed7d5d..d1a34a2 100755
--- a/test/50-assert-11-assert.bats
+++ b/test/50-assert-11-assert.bats
@@ -9,9 +9,11 @@ load test_helper
 
 @test 'assert() <expression>: returns 1 and displays <expression> if it evaluates to FALSE' {
   run assert false
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- assertion failed --' ]
-  [ "${lines[1]}" == 'expression : false' ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- assertion failed --
+expression : false
+--
+ERR_MSG
 }
diff --git a/test/50-assert-12-assert_equal.bats b/test/50-assert-12-assert_equal.bats
index af10bfa..3198584 100755
--- a/test/50-assert-12-assert_equal.bats
+++ b/test/50-assert-12-assert_equal.bats
@@ -9,38 +9,44 @@ load test_helper
 
 @test 'assert_equal() <actual> <expected>: returns 1 and displays details if <actual> does not equal <expected>' {
   run assert_equal 'a' 'b'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- values do not equal --' ]
-  [ "${lines[1]}" == 'expected : b' ]
-  [ "${lines[2]}" == 'actual   : a' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- values do not equal --
+expected : b
+actual   : a
+--
+ERR_MSG
 }
 
 @test 'assert_equal() <actual> <expected>: displays details in multi-line format if <actual> is longer than one line' {
   run assert_equal $'a 0\na 1' 'b'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- values do not equal --' ]
-  [ "${lines[1]}" == 'expected (1 lines):' ]
-  [ "${lines[2]}" == '  b' ]
-  [ "${lines[3]}" == 'actual (2 lines):' ]
-  [ "${lines[4]}" == '  a 0' ]
-  [ "${lines[5]}" == '  a 1' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- values do not equal --
+expected (1 lines):
+  b
+actual (2 lines):
+  a 0
+  a 1
+--
+ERR_MSG
 }
 
 @test 'assert_equal() <actual> <expected>: displays details in multi-line format if <expected> is longer than one line' {
   run assert_equal 'a' $'b 0\nb 1'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- values do not equal --' ]
-  [ "${lines[1]}" == 'expected (2 lines):' ]
-  [ "${lines[2]}" == '  b 0' ]
-  [ "${lines[3]}" == '  b 1' ]
-  [ "${lines[4]}" == 'actual (1 lines):' ]
-  [ "${lines[5]}" == '  a' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- values do not equal --
+expected (2 lines):
+  b 0
+  b 1
+actual (1 lines):
+  a
+--
+ERR_MSG
 }
 
 @test 'assert_equal() <actual> <expected>: performs literal matching' {
diff --git a/test/50-assert-13-assert_success.bats b/test/50-assert-13-assert_success.bats
index 65c23f5..66f5aa7 100755
--- a/test/50-assert-13-assert_success.bats
+++ b/test/50-assert-13-assert_success.bats
@@ -5,6 +5,7 @@ load test_helper
 @test "assert_success(): returns 0 if \`\$status' is 0" {
   run true
   run assert_success
+
   assert_test_pass
 }
 
@@ -12,24 +13,28 @@ load test_helper
   run bash -c 'echo "a"
                exit 1'
   run assert_success
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- command failed --' ]
-  [ "${lines[1]}" == 'status : 1' ]
-  [ "${lines[2]}" == 'output : a' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- command failed --
+status : 1
+output : a
+--
+ERR_MSG
 }
 
 @test "assert_success(): displays \`\$output' in multi-line format if it is longer than one line" {
   run bash -c 'printf "a 0\na 1"
                exit 1'
   run assert_success
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 6 ]
-  [ "${lines[0]}" == '-- command failed --' ]
-  [ "${lines[1]}" == 'status : 1' ]
-  [ "${lines[2]}" == 'output (2 lines):' ]
-  [ "${lines[3]}" == '  a 0' ]
-  [ "${lines[4]}" == '  a 1' ]
-  [ "${lines[5]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- command failed --
+status : 1
+output (2 lines):
+  a 0
+  a 1
+--
+ERR_MSG
 }
diff --git a/test/50-assert-14-assert_failure.bats b/test/50-assert-14-assert_failure.bats
index 21b9999..6291afe 100755
--- a/test/50-assert-14-assert_failure.bats
+++ b/test/50-assert-14-assert_failure.bats
@@ -12,24 +12,28 @@ load test_helper
   run bash -c 'echo "a"
                exit 0'
   run assert_failure
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- command succeeded, but it was expected to fail --' ]
-  [ "${lines[1]}" == 'output : a' ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- command succeeded, but it was expected to fail --
+output : a
+--
+ERR_MSG
 }
 
 @test "assert_failure(): displays \`\$output' in multi-line format if it is longer then one line" {
   run bash -c 'printf "a 0\na 1"
                exit 0'
   run assert_failure
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- command succeeded, but it was expected to fail --' ]
-  [ "${lines[1]}" == 'output (2 lines):' ]
-  [ "${lines[2]}" == '  a 0' ]
-  [ "${lines[3]}" == '  a 1' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- command succeeded, but it was expected to fail --
+output (2 lines):
+  a 0
+  a 1
+--
+ERR_MSG
 }
 
 @test "assert_failure() <status>: returns 0 if \`\$status' equals <status>" {
@@ -42,26 +46,30 @@ load test_helper
   run bash -c 'echo "a"
                exit 1'
   run assert_failure 2
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- command failed as expected, but status differs --' ]
-  [ "${lines[1]}" == 'expected : 2' ]
-  [ "${lines[2]}" == 'actual   : 1' ]
-  [ "${lines[3]}" == 'output   : a' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- command failed as expected, but status differs --
+expected : 2
+actual   : 1
+output   : a
+--
+ERR_MSG
 }
 
 @test "assert_failure() <status>: displays \`\$output' in multi-line format if it is longer then one line" {
   run bash -c 'printf "a 0\na 1"
                exit 1'
   run assert_failure 2
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- command failed as expected, but status differs --' ]
-  [ "${lines[1]}" == 'expected : 2' ]
-  [ "${lines[2]}" == 'actual   : 1' ]
-  [ "${lines[3]}" == 'output (2 lines):' ]
-  [ "${lines[4]}" == '  a 0' ]
-  [ "${lines[5]}" == '  a 1' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- command failed as expected, but status differs --
+expected : 2
+actual   : 1
+output (2 lines):
+  a 0
+  a 1
+--
+ERR_MSG
 }
diff --git a/test/50-assert-15-assert_output.bats b/test/50-assert-15-assert_output.bats
index 19ad6a5..6cf1b9d 100755
--- a/test/50-assert-15-assert_output.bats
+++ b/test/50-assert-15-assert_output.bats
@@ -16,12 +16,14 @@ load test_helper
 @test "assert_output() <expected>: returns 1 and displays details if <expected> does not equal \`\$output'" {
   run echo 'b'
   run assert_output 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- output differs --' ]
-  [ "${lines[1]}" == 'expected : a' ]
-  [ "${lines[2]}" == 'actual   : b' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output differs --
+expected : a
+actual   : b
+--
+ERR_MSG
 }
 
 @test 'assert_output() - : reads <expected> from STDIN' {
@@ -29,6 +31,7 @@ load test_helper
   run assert_output - <<STDIN
 a
 STDIN
+
   assert_test_pass
 }
 
@@ -37,6 +40,7 @@ STDIN
   run assert_output --stdin <<STDIN
 a
 STDIN
+
   assert_test_pass
 }
 
@@ -44,29 +48,33 @@ STDIN
 @test "assert_output() <expected>: displays details in multi-line format if \`\$output' is longer than one line" {
   run printf 'b 0\nb 1'
   run assert_output 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- output differs --' ]
-  [ "${lines[1]}" == 'expected (1 lines):' ]
-  [ "${lines[2]}" == '  a' ]
-  [ "${lines[3]}" == 'actual (2 lines):' ]
-  [ "${lines[4]}" == '  b 0' ]
-  [ "${lines[5]}" == '  b 1' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output differs --
+expected (1 lines):
+  a
+actual (2 lines):
+  b 0
+  b 1
+--
+ERR_MSG
 }
 
 @test 'assert_output() <expected>: displays details in multi-line format if <expected> is longer than one line' {
   run echo 'b'
   run assert_output $'a 0\na 1'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- output differs --' ]
-  [ "${lines[1]}" == 'expected (2 lines):' ]
-  [ "${lines[2]}" == '  a 0' ]
-  [ "${lines[3]}" == '  a 1' ]
-  [ "${lines[4]}" == 'actual (1 lines):' ]
-  [ "${lines[5]}" == '  b' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output differs --
+expected (2 lines):
+  a 0
+  a 1
+actual (1 lines):
+  b
+--
+ERR_MSG
 }
 
 # Options
@@ -103,41 +111,47 @@ STDIN
 @test "assert_output() --partial <partial>: returns 1 and displays details if <partial> is not a substring in \`\$output'" {
   run echo 'b'
   run assert_output --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- output does not contain substring --' ]
-  [ "${lines[1]}" == 'substring : a' ]
-  [ "${lines[2]}" == 'output    : b' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output does not contain substring --
+substring : a
+output    : b
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "assert_output() --partial <partial>: displays details in multi-line format if \`\$output' is longer than one line" {
   run printf 'b 0\nb 1'
   run assert_output --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- output does not contain substring --' ]
-  [ "${lines[1]}" == 'substring (1 lines):' ]
-  [ "${lines[2]}" == '  a' ]
-  [ "${lines[3]}" == 'output (2 lines):' ]
-  [ "${lines[4]}" == '  b 0' ]
-  [ "${lines[5]}" == '  b 1' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output does not contain substring --
+substring (1 lines):
+  a
+output (2 lines):
+  b 0
+  b 1
+--
+ERR_MSG
 }
 
 @test 'assert_output() --partial <partial>: displays details in multi-line format if <partial> is longer than one line' {
   run echo 'b'
   run assert_output --partial $'a 0\na 1'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- output does not contain substring --' ]
-  [ "${lines[1]}" == 'substring (2 lines):' ]
-  [ "${lines[2]}" == '  a 0' ]
-  [ "${lines[3]}" == '  a 1' ]
-  [ "${lines[4]}" == 'output (1 lines):' ]
-  [ "${lines[5]}" == '  b' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output does not contain substring --
+substring (2 lines):
+  a 0
+  a 1
+output (1 lines):
+  b
+--
+ERR_MSG
 }
 
 
@@ -167,51 +181,59 @@ STDIN
 @test "assert_output() --regexp <regexp>: returns 1 and displays details if <regexp> does not match \`\$output'" {
   run echo 'b'
   run assert_output --regexp '.*a.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- regular expression does not match output --' ]
-  [ "${lines[1]}" == 'regexp : .*a.*' ]
-  [ "${lines[2]}" == 'output : b' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- regular expression does not match output --
+regexp : .*a.*
+output : b
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "assert_output() --regexp <regexp>: displays details in multi-line format if \`\$output' is longer than one line" {
   run printf 'b 0\nb 1'
   run assert_output --regexp '.*a.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- regular expression does not match output --' ]
-  [ "${lines[1]}" == 'regexp (1 lines):' ]
-  [ "${lines[2]}" == '  .*a.*' ]
-  [ "${lines[3]}" == 'output (2 lines):' ]
-  [ "${lines[4]}" == '  b 0' ]
-  [ "${lines[5]}" == '  b 1' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- regular expression does not match output --
+regexp (1 lines):
+  .*a.*
+output (2 lines):
+  b 0
+  b 1
+--
+ERR_MSG
 }
 
 @test 'assert_output() --regexp <regexp>: displays details in multi-line format if <regexp> is longer than one line' {
   run echo 'b'
   run assert_output --regexp $'.*a\nb.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- regular expression does not match output --' ]
-  [ "${lines[1]}" == 'regexp (2 lines):' ]
-  [ "${lines[2]}" == '  .*a' ]
-  [ "${lines[3]}" == '  b.*' ]
-  [ "${lines[4]}" == 'output (1 lines):' ]
-  [ "${lines[5]}" == '  b' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- regular expression does not match output --
+regexp (2 lines):
+  .*a
+  b.*
+output (1 lines):
+  b
+--
+ERR_MSG
 }
 
 # Error handling
 @test 'assert_output() --regexp <regexp>: returns 1 and displays an error message if <regexp> is not a valid extended regular expression' {
   run assert_output --regexp '[.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: assert_output --' ]
-  [ "${lines[1]}" == "Invalid extended regular expression: \`[.*'" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: assert_output --
+Invalid extended regular expression: `[.*'
+--
+ERR_MSG
 }
 
 
@@ -221,11 +243,13 @@ STDIN
 
 @test "assert_output(): \`--partial' and \`--regexp' are mutually exclusive" {
   run assert_output --partial --regexp
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: assert_output --' ]
-  [ "${lines[1]}" == "\`--partial' and \`--regexp' are mutually exclusive" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: assert_output --
+`--partial' and `--regexp' are mutually exclusive
+--
+ERR_MSG
 }
 
 @test "assert_output(): \`--' stops parsing options" {
diff --git a/test/50-assert-16-refute_output.bats b/test/50-assert-16-refute_output.bats
index 6b29ff7..b0b6559 100755
--- a/test/50-assert-16-refute_output.bats
+++ b/test/50-assert-16-refute_output.bats
@@ -17,11 +17,13 @@ load test_helper
 @test "refute_output() <unexpected>: returns 1 and displays details if <unexpected> equals \`\$output'" {
   run echo 'a'
   run refute_output 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- output equals, but it was expected to differ --' ]
-  [ "${lines[1]}" == 'output : a' ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output equals, but it was expected to differ --
+output : a
+--
+ERR_MSG
 }
 
 @test 'refute_output() - : reads <unexpected> from STDIN' {
@@ -46,13 +48,15 @@ INPUT
 @test 'refute_output() <unexpected>: displays details in multi-line format if necessary' {
   run printf 'a 0\na 1'
   run refute_output $'a 0\na 1'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- output equals, but it was expected to differ --' ]
-  [ "${lines[1]}" == 'output (2 lines):' ]
-  [ "${lines[2]}" == '  a 0' ]
-  [ "${lines[3]}" == '  a 1' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output equals, but it was expected to differ --
+output (2 lines):
+  a 0
+  a 1
+--
+ERR_MSG
 }
 
 # Options
@@ -92,27 +96,31 @@ test_p_partial () {
 @test "refute_output() --partial <partial>: returns 1 and displays details if <partial> is a substring in \`\$output'" {
   run echo 'a'
   run refute_output --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- output should not contain substring --' ]
-  [ "${lines[1]}" == 'substring : a' ]
-  [ "${lines[2]}" == 'output    : a' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output should not contain substring --
+substring : a
+output    : a
+--
+ERR_MSG
 }
 
 # Output formatting
 @test 'refute_output() --partial <partial>: displays details in multi-line format if necessary' {
   run printf 'a 0\na 1'
   run refute_output --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- output should not contain substring --' ]
-  [ "${lines[1]}" == 'substring (1 lines):' ]
-  [ "${lines[2]}" == '  a' ]
-  [ "${lines[3]}" == 'output (2 lines):' ]
-  [ "${lines[4]}" == '  a 0' ]
-  [ "${lines[5]}" == '  a 1' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output should not contain substring --
+substring (1 lines):
+  a
+output (2 lines):
+  a 0
+  a 1
+--
+ERR_MSG
 }
 
 
@@ -145,37 +153,43 @@ test_r_regexp () {
 @test "refute_output() --regexp <regexp>: returns 1 and displays details if <regexp> matches \`\$output'" {
   run echo 'a'
   run refute_output --regexp '.*a.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- regular expression should not match output --' ]
-  [ "${lines[1]}" == 'regexp : .*a.*' ]
-  [ "${lines[2]}" == 'output : a' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- regular expression should not match output --
+regexp : .*a.*
+output : a
+--
+ERR_MSG
 }
 
 # Output formatting
 @test 'refute_output() --regexp <regexp>: displays details in multi-line format if necessary' {
   run printf 'a 0\na 1'
   run refute_output --regexp '.*a.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 7 ]
-  [ "${lines[0]}" == '-- regular expression should not match output --' ]
-  [ "${lines[1]}" == 'regexp (1 lines):' ]
-  [ "${lines[2]}" == '  .*a.*' ]
-  [ "${lines[3]}" == 'output (2 lines):' ]
-  [ "${lines[4]}" == '  a 0' ]
-  [ "${lines[5]}" == '  a 1' ]
-  [ "${lines[6]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- regular expression should not match output --
+regexp (1 lines):
+  .*a.*
+output (2 lines):
+  a 0
+  a 1
+--
+ERR_MSG
 }
 
 # Error handling
 @test 'refute_output() --regexp <regexp>: returns 1 and displays an error message if <regexp> is not a valid extended regular expression' {
   run refute_output --regexp '[.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: refute_output --' ]
-  [ "${lines[1]}" == "Invalid extended regular expression: \`[.*'" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: refute_output --
+Invalid extended regular expression: `[.*'
+--
+ERR_MSG
 }
 
 
@@ -185,11 +199,13 @@ test_r_regexp () {
 
 @test "refute_output(): \`--partial' and \`--regexp' are mutually exclusive" {
   run refute_output --partial --regexp
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: refute_output --' ]
-  [ "${lines[1]}" == "\`--partial' and \`--regexp' are mutually exclusive" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: refute_output --
+`--partial' and `--regexp' are mutually exclusive
+--
+ERR_MSG
 }
 
 @test "refute_output(): \`--' stops parsing options" {
diff --git a/test/50-assert-17-assert_line.bats b/test/50-assert-17-assert_line.bats
index 0d178dd..d0f7103 100755
--- a/test/50-assert-17-assert_line.bats
+++ b/test/50-assert-17-assert_line.bats
@@ -21,26 +21,30 @@ load test_helper
 @test "assert_line() <expected>: returns 1 and displays details if <expected> is not a line in \`\${lines[@]}'" {
   run echo 'b'
   run assert_line 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- output does not contain line --' ]
-  [ "${lines[1]}" == 'line   : a' ]
-  [ "${lines[2]}" == 'output : b' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output does not contain line --
+line   : a
+output : b
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "assert_line() <expected>: displays \`\$output' in multi-line format if it is longer than one line" {
   run printf 'b 0\nb 1'
   run assert_line 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 6 ]
-  [ "${lines[0]}" == '-- output does not contain line --' ]
-  [ "${lines[1]}" == 'line : a' ]
-  [ "${lines[2]}" == 'output (2 lines):' ]
-  [ "${lines[3]}" == '  b 0' ]
-  [ "${lines[4]}" == '  b 1' ]
-  [ "${lines[5]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- output does not contain line --
+line : a
+output (2 lines):
+  b 0
+  b 1
+--
+ERR_MSG
 }
 
 # Options
@@ -80,26 +84,30 @@ test_p_partial () {
 @test "assert_line() --partial <partial>: returns 1 and displays details if <partial> is not a substring in any lines in \`\${lines[@]}'" {
   run echo 'b'
   run assert_line --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- no output line contains substring --' ]
-  [ "${lines[1]}" == 'substring : a' ]
-  [ "${lines[2]}" == 'output    : b' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no output line contains substring --
+substring : a
+output    : b
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "assert_line() --partial <partial>: displays \`\$output' in multi-line format if it is longer than one line" {
   run printf 'b 0\nb 1'
   run assert_line --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 6 ]
-  [ "${lines[0]}" == '-- no output line contains substring --' ]
-  [ "${lines[1]}" == 'substring : a' ]
-  [ "${lines[2]}" == 'output (2 lines):' ]
-  [ "${lines[3]}" == '  b 0' ]
-  [ "${lines[4]}" == '  b 1' ]
-  [ "${lines[5]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no output line contains substring --
+substring : a
+output (2 lines):
+  b 0
+  b 1
+--
+ERR_MSG
 }
 
 
@@ -132,26 +140,30 @@ test_r_regexp () {
 @test "assert_line() --regexp <regexp>: returns 1 and displays details if <regexp> does not match any lines in \`\${lines[@]}'" {
   run echo 'b'
   run assert_line --regexp '^.a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- no output line matches regular expression --' ]
-  [ "${lines[1]}" == 'regexp : ^.a' ]
-  [ "${lines[2]}" == 'output : b' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no output line matches regular expression --
+regexp : ^.a
+output : b
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "assert_line() --regexp <regexp>: displays \`\$output' in multi-line format if longer than one line" {
   run printf 'b 0\nb 1'
   run assert_line --regexp '^.a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 6 ]
-  [ "${lines[0]}" == '-- no output line matches regular expression --' ]
-  [ "${lines[1]}" == 'regexp : ^.a' ]
-  [ "${lines[2]}" == 'output (2 lines):' ]
-  [ "${lines[3]}" == '  b 0' ]
-  [ "${lines[4]}" == '  b 1' ]
-  [ "${lines[5]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no output line matches regular expression --
+regexp : ^.a
+output (2 lines):
+  b 0
+  b 1
+--
+ERR_MSG
 }
 
 
@@ -176,11 +188,13 @@ test_n_index () {
 
 @test 'assert_line() --index <idx>: returns 1 and displays an error message if <idx> is not an integer' {
   run assert_line --index 1a
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: assert_line --' ]
-  [ "${lines[1]}" == "\`--index' requires an integer argument: \`1a'" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: assert_line --
+`--index' requires an integer argument: `1a'
+--
+ERR_MSG
 }
 
 
@@ -198,13 +212,15 @@ test_n_index () {
 @test "assert_line() --index <idx> <expected>: returns 1 and displays details if <expected> does not equal \`\${lines[<idx>]}'" {
   run printf 'a\nb\nc'
   run assert_line --index 1 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- line differs --' ]
-  [ "${lines[1]}" == 'index    : 1' ]
-  [ "${lines[2]}" == 'expected : a' ]
-  [ "${lines[3]}" == 'actual   : b' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- line differs --
+index    : 1
+expected : a
+actual   : b
+--
+ERR_MSG
 }
 
 # Options
@@ -244,13 +260,15 @@ test_index_p_partial () {
 @test "assert_line() --index <idx> --partial <partial>: returns 1 and displays details if <partial> is not a substring in \`\${lines[<idx>]}'" {
   run printf 'b 0\nb 1'
   run assert_line --index 1 --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- line does not contain substring --' ]
-  [ "${lines[1]}" == 'index     : 1' ]
-  [ "${lines[2]}" == 'substring : a' ]
-  [ "${lines[3]}" == 'line      : b 1' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- line does not contain substring --
+index     : 1
+substring : a
+line      : b 1
+--
+ERR_MSG
 }
 
 
@@ -283,13 +301,15 @@ test_index_r_regexp () {
 @test "assert_line() --index <idx> --regexp <regexp>: returns 1 and displays details if <regexp> does not match \`\${lines[<idx>]}'" {
   run printf 'a\nb\nc'
   run assert_line --index 1 --regexp '^.a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- regular expression does not match line --' ]
-  [ "${lines[1]}" == 'index  : 1' ]
-  [ "${lines[2]}" == 'regexp : ^.a' ]
-  [ "${lines[3]}" == 'line   : b' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- regular expression does not match line --
+index  : 1
+regexp : ^.a
+line   : b
+--
+ERR_MSG
 }
 
 
@@ -299,20 +319,24 @@ test_index_r_regexp () {
 
 @test "assert_line(): \`--partial' and \`--regexp' are mutually exclusive" {
   run assert_line --partial --regexp
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: assert_line --' ]
-  [ "${lines[1]}" == "\`--partial' and \`--regexp' are mutually exclusive" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: assert_line --
+`--partial' and `--regexp' are mutually exclusive
+--
+ERR_MSG
 }
 
 @test 'assert_line() --regexp <regexp>: returns 1 and displays an error message if <regexp> is not a valid extended regular expression' {
   run assert_line --regexp '[.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: assert_line --' ]
-  [ "${lines[1]}" == "Invalid extended regular expression: \`[.*'" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: assert_line --
+Invalid extended regular expression: `[.*'
+--
+ERR_MSG
 }
 
 @test "assert_line(): \`--' stops parsing options" {
diff --git a/test/50-assert-18-refute_line.bats b/test/50-assert-18-refute_line.bats
index 5d77066..a26b0ba 100755
--- a/test/50-assert-18-refute_line.bats
+++ b/test/50-assert-18-refute_line.bats
@@ -21,29 +21,33 @@ load test_helper
 @test "refute_line() <unexpected>: returns 1 and displays details if <unexpected> is not a line in \`\${lines[@]}'" {
   run echo 'a'
   run refute_line 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- line should not be in output --' ]
-  [ "${lines[1]}" == 'line   : a' ]
-  [ "${lines[2]}" == 'index  : 0' ]
-  [ "${lines[3]}" == 'output : a' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- line should not be in output --
+line   : a
+index  : 0
+output : a
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "refute_line() <unexpected>: displays \`\$output' in multi-line format if it is longer than one line" {
   run printf 'a 0\na 1\na 2'
   run refute_line 'a 1'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 8 ]
-  [ "${lines[0]}" == '-- line should not be in output --' ]
-  [ "${lines[1]}" == 'line  : a 1' ]
-  [ "${lines[2]}" == 'index : 1' ]
-  [ "${lines[3]}" == 'output (3 lines):' ]
-  [ "${lines[4]}" == '  a 0' ]
-  [ "${lines[5]}" == '> a 1' ]
-  [ "${lines[6]}" == '  a 2' ]
-  [ "${lines[7]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- line should not be in output --
+line  : a 1
+index : 1
+output (3 lines):
+  a 0
+> a 1
+  a 2
+--
+ERR_MSG
 }
 
 # Options
@@ -83,29 +87,33 @@ test_p_partial () {
 @test "refute_line() --partial <partial>: returns 1 and displays details if <partial> is a substring in any line in \`\${lines[@]}'" {
   run echo 'a'
   run refute_line --partial 'a'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- no line should contain substring --' ]
-  [ "${lines[1]}" == 'substring : a' ]
-  [ "${lines[2]}" == 'index     : 0' ]
-  [ "${lines[3]}" == 'output    : a' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no line should contain substring --
+substring : a
+index     : 0
+output    : a
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "refute_line() --partial <partial>: displays \`\$output' in multi-line format if it is longer than one line" {
   run printf 'a\nabc\nc'
   run refute_line --partial 'b'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 8 ]
-  [ "${lines[0]}" == '-- no line should contain substring --' ]
-  [ "${lines[1]}" == 'substring : b' ]
-  [ "${lines[2]}" == 'index     : 1' ]
-  [ "${lines[3]}" == 'output (3 lines):' ]
-  [ "${lines[4]}" == '  a' ]
-  [ "${lines[5]}" == '> abc' ]
-  [ "${lines[6]}" == '  c' ]
-  [ "${lines[7]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no line should contain substring --
+substring : b
+index     : 1
+output (3 lines):
+  a
+> abc
+  c
+--
+ERR_MSG
 }
 
 
@@ -138,29 +146,33 @@ test_r_regexp () {
 @test "refute_line() --regexp <regexp>: returns 1 and displays details if <regexp> matches any lines in \`\${lines[@]}'" {
   run echo 'a'
   run refute_line --regexp '.*a.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- no line should match the regular expression --' ]
-  [ "${lines[1]}" == 'regexp : .*a.*' ]
-  [ "${lines[2]}" == 'index  : 0' ]
-  [ "${lines[3]}" == 'output : a' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no line should match the regular expression --
+regexp : .*a.*
+index  : 0
+output : a
+--
+ERR_MSG
 }
 
 # Output formatting
 @test "refute_line() --regexp <regexp>: displays \`\$output' in multi-line format if longer than one line" {
   run printf 'a\nabc\nc'
   run refute_line --regexp '.*b.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 8 ]
-  [ "${lines[0]}" == '-- no line should match the regular expression --' ]
-  [ "${lines[1]}" == 'regexp : .*b.*' ]
-  [ "${lines[2]}" == 'index  : 1' ]
-  [ "${lines[3]}" == 'output (3 lines):' ]
-  [ "${lines[4]}" == '  a' ]
-  [ "${lines[5]}" == '> abc' ]
-  [ "${lines[6]}" == '  c' ]
-  [ "${lines[7]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- no line should match the regular expression --
+regexp : .*b.*
+index  : 1
+output (3 lines):
+  a
+> abc
+  c
+--
+ERR_MSG
 }
 
 
@@ -185,11 +197,13 @@ test_n_index () {
 
 @test 'refute_line() --index <idx>: returns 1 and displays an error message if <idx> is not an integer' {
   run refute_line --index 1a
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: refute_line --' ]
-  [ "${lines[1]}" == "\`--index' requires an integer argument: \`1a'" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: refute_line --
+`--index' requires an integer argument: `1a'
+--
+ERR_MSG
 }
 
 
@@ -207,12 +221,14 @@ test_n_index () {
 @test "refute_line() --index <idx> <unexpected>: returns 1 and displays details if <unexpected> equals \`\${lines[<idx>]}'" {
   run printf 'a\nb\nc'
   run refute_line --index 1 'b'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 4 ]
-  [ "${lines[0]}" == '-- line should differ --' ]
-  [ "${lines[1]}" == 'index : 1' ]
-  [ "${lines[2]}" == 'line  : b' ]
-  [ "${lines[3]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- line should differ --
+index : 1
+line  : b
+--
+ERR_MSG
 }
 
 # Options
@@ -252,13 +268,15 @@ test_index_p_partial () {
 @test "refute_line() --index <idx> --partial <partial>: returns 1 and displays details if <partial> is a substring in \`\${lines[<idx>]}'" {
   run printf 'a\nabc\nc'
   run refute_line --index 1 --partial 'b'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- line should not contain substring --' ]
-  [ "${lines[1]}" == 'index     : 1' ]
-  [ "${lines[2]}" == 'substring : b' ]
-  [ "${lines[3]}" == 'line      : abc' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- line should not contain substring --
+index     : 1
+substring : b
+line      : abc
+--
+ERR_MSG
 }
 
 
@@ -291,13 +309,15 @@ test_index_r_regexp () {
 @test "refute_line() --index <idx> --regexp <regexp>: returns 1 and displays details if <regexp> matches \`\${lines[<idx>]}'" {
   run printf 'a\nabc\nc'
   run refute_line --index 1 --regexp '.*b.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 5 ]
-  [ "${lines[0]}" == '-- regular expression should not match line --' ]
-  [ "${lines[1]}" == 'index  : 1' ]
-  [ "${lines[2]}" == 'regexp : .*b.*' ]
-  [ "${lines[3]}" == 'line   : abc' ]
-  [ "${lines[4]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- regular expression should not match line --
+index  : 1
+regexp : .*b.*
+line   : abc
+--
+ERR_MSG
 }
 
 
@@ -307,20 +327,24 @@ test_index_r_regexp () {
 
 @test "refute_line(): \`--partial' and \`--regexp' are mutually exclusive" {
   run refute_line --partial --regexp
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: refute_line --' ]
-  [ "${lines[1]}" == "\`--partial' and \`--regexp' are mutually exclusive" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: refute_line --
+`--partial' and `--regexp' are mutually exclusive
+--
+ERR_MSG
 }
 
 @test 'refute_line() --regexp <regexp>: returns 1 and displays an error message if <regexp> is not a valid extended regular expression' {
   run refute_line --regexp '[.*'
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- ERROR: refute_line --' ]
-  [ "${lines[1]}" == "Invalid extended regular expression: \`[.*'" ]
-  [ "${lines[2]}" == '--' ]
+
+  assert_test_fail <<'ERR_MSG'
+
+-- ERROR: refute_line --
+Invalid extended regular expression: `[.*'
+--
+ERR_MSG
 }
 
 @test "refute_line(): \`--' stops parsing options" {
diff --git a/test/50-assert-19-refute.bats b/test/50-assert-19-refute.bats
index 31524fa..f9e2737 100755
--- a/test/50-assert-19-refute.bats
+++ b/test/50-assert-19-refute.bats
@@ -9,9 +9,10 @@ load test_helper
 
 @test 'refute() <expression>: returns 1 and displays <expression> if it evaluates to TRUE' {
   run refute true
-  [ "$status" -eq 1 ]
-  [ "${#lines[@]}" -eq 3 ]
-  [ "${lines[0]}" == '-- assertion succeeded, but it was expected to fail --' ]
-  [ "${lines[1]}" == 'expression : true' ]
-  [ "${lines[2]}" == '--' ]
+  assert_test_fail <<'ERR_MSG'
+
+-- assertion succeeded, but it was expected to fail --
+expression : true
+--
+ERR_MSG
 }
diff --git a/test/test_helper.bash b/test/test_helper.bash
index 77927fe..1461696 100644
--- a/test/test_helper.bash
+++ b/test/test_helper.bash
@@ -12,4 +12,14 @@ setup() {
     test "$status" -eq 0
     test "${#lines[@]}" -eq 0
   }
+
+  assert_test_fail() {
+    local err_msg="${1-$(cat -)}"
+    local num_lines="$(printf '%s' "$err_msg" | wc -l)"
+
+
+    test "$status" -eq 1
+    test "${#lines[@]}" -eq "$num_lines"
+    test "$output" == "$err_msg"
+  }
 }