var BITWISE_FEATURE_A = 1;
var BITWISE_FEATURE_B = BITWISE_FEATURE_A<<1;
var BITWISE_FEATURE_C = BITWISE_FEATURE_B<<1;
var BITWISE_ENABLED = BITWISE_FEATURE_A ^ BITWISE_FEATURE_C;
var STRING_FEATURE_A = "yellow_scrollbar";
var STRING_FEATURE_B = "green_box";
var STRING_FEATURE_C = "blue_banner";
var STRING_ENABLED = STRING_FEATURE_A + STRING_FEATURE_C;
BITWISE_ENABLED & BITWISE_FEATURE_A === BITWISE_FEATURE_A
BITWISE_ENABLED & BITWISE_FEATURE_B === BITWISE_FEATURE_B
STRING_ENABLED.indexOf(STRING_FEATURE_C) !== -1
STRING_ENABLED.indexOf(STRING_FEATURE_B) !== -1
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
Bitwise - Existing | |
Bitwise - Non-Existing | |
String - Existing | |
String - Non-Existing |
Test name | Executions per second |
---|---|
Bitwise - Existing | 379446.3 Ops/sec |
Bitwise - Non-Existing | 386021.7 Ops/sec |
String - Existing | 563627.4 Ops/sec |
String - Non-Existing | 506159.6 Ops/sec |
I'll break down the provided JSON and explain what's being tested, compared, and the pros/cons of each approach.
Benchmark Definition
The benchmark defines two feature flags:
BITWISE_FEATURE_A
(an integer value)STRING_FEATURE_A
, STRING_FEATURE_B
, and STRING_FEATURE_C
(string values)Two bitwise operations are performed on these feature flags:
* BITWISE_FEATURE_A << 1
(left shift by 1 bit)
* BITWISE_FEATURE_B << 1
(left shift by 1 bit, which is not a valid operation since BITWISE_FEATURE_B
is not defined)
Additionally, two string operations are performed:
* Concatenation: STRING_ENABLED = STRING_FEATURE_A + STRING_FEATURE_C
The benchmark consists of four test cases:
Test Cases
BITWISE_ENABLED
and BITWISE_FEATURE_A
equals BITWISE_FEATURE_A
. (BITWISE_ENABLED & BITWISE_FEATURE_A === BITWISE_FEATURE_A
)BITWISE_ENABLED
and BITWISE_FEATURE_B
equals BITWISE_FEATURE_B
. (Note: BITWISE_FEATURE_B
is not defined in the benchmark definition)STRING_ENABLED
contains STRING_FEATURE_C
. (STRING_ENABLED.indexOf(STRING_FEATURE_C) !== -1
)STRING_ENABLED
contains STRING_FEATURE_B
. (Note: STRING_FEATURE_B
is not defined in the benchmark definition)Comparison
The test cases are comparing the behavior of bitwise and string operations on these feature flags.
BITWISE_FEATURE_A << 1
is a valid operation since it's performing a left shift by 1 bit.BITWISE_FEATURE_B << 1
is not a valid operation since BITWISE_FEATURE_B
is not defined. This might indicate an error or omission in the benchmark definition.STRING_ENABLED = STRING_FEATURE_A + STRING_FEATURE_C
STRING_ENABLED.indexOf(STRING_FEATURE_C)
and STRING_ENABLED.indexOf(STRING_FEATURE_B)
Pros/Cons of each approach
BITWISE_FEATURE_B
is not defined, and attempting to perform a bitwise AND operation will result in an error or undefined behavior.STRING_FEATURE_B
not being defined.Other Considerations
BITWISE_FEATURE_B
).Alternatives
Other alternatives for running microbenchmarks on JavaScript could include:
Benchmark.js
or Benchmark-chrome
process.cpuTimeDomain
)benchmarks
tool