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alessandrocuzzocrea/chip-8-emulator-js

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Showing 76 of 76 total issues

Similar blocks of code found in 2 locations. Consider refactoring.
Open

function _onKeyUp(key) {
  // prettier-ignore
  switch(key){
    case c.keys["1"]: keys["1"] = false; break;
    case c.keys["2"]: keys["2"] = false; break;
Severity: Major
Found in src/keyboard.js and 1 other location - About 2 days to fix
src/keyboard.js on lines 43..63

Duplicated Code

Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

Tuning

This issue has a mass of 399.

We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

Refactorings

Further Reading

Similar blocks of code found in 2 locations. Consider refactoring.
Open

function _onKeyDown(key) {
  // prettier-ignore
  switch(key){
    case c.keys["1"]: keys["1"] = true; break;
    case c.keys["2"]: keys["2"] = true; break;
Severity: Major
Found in src/keyboard.js and 1 other location - About 2 days to fix
src/keyboard.js on lines 65..85

Duplicated Code

Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

Tuning

This issue has a mass of 399.

We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

Refactorings

Further Reading

Function decode has a Cognitive Complexity of 90 (exceeds 5 allowed). Consider refactoring.
Open

function decode(chip, opcode, keyboard, logger) {
  const a = (opcode >> 12) & 0xf;
  const b = (opcode >> 8) & 0xf;
  const c = (opcode >> 4) & 0xf;
  const d = opcode & 0xf;
Severity: Minor
Found in src/chip8.js - About 1 day to fix

Cognitive Complexity

Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

A method's cognitive complexity is based on a few simple rules:

  • Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
  • Code is considered more complex for each "break in the linear flow of the code"
  • Code is considered more complex when "flow breaking structures are nested"

Further reading

File chip8.js has 625 lines of code (exceeds 250 allowed). Consider refactoring.
Open

const cloneDeep = require("lodash/cloneDeep");
const values = require("lodash/values");
const range = require("lodash/range");

const consts = require("./consts");
Severity: Major
Found in src/chip8.js - About 1 day to fix

    Function decode has 193 lines of code (exceeds 25 allowed). Consider refactoring.
    Open

    function decode(chip, opcode, keyboard, logger) {
  const a = (opcode >> 12) & 0xf;
  const b = (opcode >> 8) & 0xf;
  const c = (opcode >> 4) & 0xf;
  const d = opcode & 0xf;
    Severity: Major
    Found in src/chip8.js - About 7 hrs to fix

      Function decode2 has 135 lines of code (exceeds 25 allowed). Consider refactoring.
      Open

      function decode2(chip, pc) {
  const opcode = fetch(chip, pc);
  const a = (opcode >> 12) & 0xf;
  const b = (opcode >> 8) & 0xf;
  const c = (opcode >> 4) & 0xf;
      Severity: Major
      Found in src/chip8.js - About 5 hrs to fix

        Function decode2 has a Cognitive Complexity of 29 (exceeds 5 allowed). Consider refactoring.
        Open

        function decode2(chip, pc) {
  const opcode = fetch(chip, pc);
  const a = (opcode >> 12) & 0xf;
  const b = (opcode >> 8) & 0xf;
  const c = (opcode >> 4) & 0xf;
        Severity: Minor
        Found in src/chip8.js - About 4 hrs to fix

        Cognitive Complexity

        Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.

        A method's cognitive complexity is based on a few simple rules:

        • Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
        • Code is considered more complex for each "break in the linear flow of the code"
        • Code is considered more complex when "flow breaking structures are nested"

        Further reading

        Similar blocks of code found in 2 locations. Consider refactoring.
        Open

        function subnXY(chip8, x, y) {
  const difference = chip8.v[y] - chip8.v[x];
  chip8.v[0xf] = chip8.v[y] > chip8.v[x] ? 0x01 : 0x00;
  chip8.v[x] = difference;
  return chip8;
        Severity: Major
        Found in src/chip8.js and 1 other location - About 3 hrs to fix
        src/chip8.js on lines 154..159

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 97.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 2 locations. Consider refactoring.
        Open

        function subXY(chip8, x, y) {
  const difference = chip8.v[x] - chip8.v[y];
  chip8.v[0xf] = chip8.v[x] > chip8.v[y] ? 0x01 : 0x00;
  chip8.v[x] = difference;
  return chip8;
        Severity: Major
        Found in src/chip8.js and 1 other location - About 3 hrs to fix
        src/chip8.js on lines 168..173

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 97.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 5 locations. Consider refactoring.
        Open

            case 0x3:
      {
        // 3xkk - SE Vx, byte
        const vx = b;
        const byte = (c << 4) + d;
        Severity: Major
        Found in src/chip8.js and 4 other locations - About 2 hrs to fix
        src/chip8.js on lines 333..346
        src/chip8.js on lines 348..361
        src/chip8.js on lines 363..376
        src/chip8.js on lines 430..444

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 93.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 5 locations. Consider refactoring.
        Open

            case 0xc:
      {
        // Cxkk - RND Vx, byte
        const x = b;
        const byte = (c << 4) + d;
        Severity: Major
        Found in src/chip8.js and 4 other locations - About 2 hrs to fix
        src/chip8.js on lines 318..331
        src/chip8.js on lines 333..346
        src/chip8.js on lines 348..361
        src/chip8.js on lines 363..376

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 93.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 5 locations. Consider refactoring.
        Open

            case 0x7:
      {
        // "7xkk - ADD Vx, byte"
        const vx = b;
        const byte = (c << 4) + d;
        Severity: Major
        Found in src/chip8.js and 4 other locations - About 2 hrs to fix
        src/chip8.js on lines 318..331
        src/chip8.js on lines 333..346
        src/chip8.js on lines 348..361
        src/chip8.js on lines 430..444

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 93.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 5 locations. Consider refactoring.
        Open

            case 0x4:
      {
        // 4xkk - SNE Vx, byte
        const vx = b;
        const byte = (c << 4) + d;
        Severity: Major
        Found in src/chip8.js and 4 other locations - About 2 hrs to fix
        src/chip8.js on lines 318..331
        src/chip8.js on lines 348..361
        src/chip8.js on lines 363..376
        src/chip8.js on lines 430..444

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 93.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 5 locations. Consider refactoring.
        Open

            case 0x6:
      {
        // 6xkk - LD Vx, byte
        const vx = b;
        const byte = (c << 4) + d;
        Severity: Major
        Found in src/chip8.js and 4 other locations - About 2 hrs to fix
        src/chip8.js on lines 318..331
        src/chip8.js on lines 333..346
        src/chip8.js on lines 363..376
        src/chip8.js on lines 430..444

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 93.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 2 locations. Consider refactoring.
        Open

              if (d === 0x2) {
        const vx = b;
        const vy = c;
        if (logger)
          logger.log(
        Severity: Major
        Found in src/chip8.js and 1 other location - About 2 hrs to fix
        src/chip8.js on lines 403..411

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 88.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 2 locations. Consider refactoring.
        Open

              if (d === 0x0) {
        const vx = b;
        const vy = c;
        if (logger)
          logger.log(
        Severity: Major
        Found in src/chip8.js and 1 other location - About 2 hrs to fix
        src/chip8.js on lines 390..398

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 88.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 3 locations. Consider refactoring.
        Open

            case 0xa:
      {
        // "Annn - LD I, addr"
        const nnn = (b << 8) + (c << 4) + d;
        if (logger) logger.log(`Annn - LD I, addr: nnn=${nnn.toString(16)}`);
        Severity: Major
        Found in src/chip8.js and 2 other locations - About 2 hrs to fix
        src/chip8.js on lines 300..307
        src/chip8.js on lines 309..316

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 81.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 3 locations. Consider refactoring.
        Open

            case 0x2:
      {
        // 2nnn - CALL addr
        const nnn = (b << 8) + (c << 4) + d;
        if (logger) logger.log(`2nnn - CALL addr: nnn=${nnn.toString(16)}`);
        Severity: Major
        Found in src/chip8.js and 2 other locations - About 2 hrs to fix
        src/chip8.js on lines 300..307
        src/chip8.js on lines 414..421

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 81.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 3 locations. Consider refactoring.
        Open

            case 0x1:
      {
        // 1nnn - JP addr
        const nnn = (b << 8) + (c << 4) + d;
        if (logger) logger.log(`1nnn - JP addr: nnn=${nnn.toString(16)}`);
        Severity: Major
        Found in src/chip8.js and 2 other locations - About 2 hrs to fix
        src/chip8.js on lines 309..316
        src/chip8.js on lines 414..421

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 81.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Similar blocks of code found in 6 locations. Consider refactoring.
        Open

              if (c === 0x1 && d === 0x5) {
        const x = b;
        if (logger) logger.log(`Fx15 - LD DT, Vx, Vx=${x.toString(16)}`);
        return module.exports.ldDTVx(chip, x);
      }
        Severity: Major
        Found in src/chip8.js and 5 other locations - About 2 hrs to fix
        src/chip8.js on lines 461..465
        src/chip8.js on lines 474..478
        src/chip8.js on lines 480..484
        src/chip8.js on lines 486..490
        src/chip8.js on lines 492..496

        Duplicated Code

        Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:

        Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.

        When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).

        Tuning

        This issue has a mass of 78.

        We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.

        The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.

        If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.

        See codeclimate-duplication's documentation for more information about tuning the mass threshold in your .codeclimate.yml.

        Refactorings

        Further Reading

        Severity
        Category
        Status
        Source
        Language