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alessandrocuzzocrea/chip-8-emulator-js

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Showing 26 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

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

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

      if (c === 0x2 && d === 0x9) {
        const x = b;
        if (logger) logger.log(`Fx29, Vx=${x.toString(16)}`);
        return module.exports.ldFVx(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 468..472
src/chip8.js on lines 474..478
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

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

      if (c === 0x5 && d === 0x5) {
        const x = b;
        if (logger) logger.log(`Fx55, Vx=${x.toString(16)}`);
        return module.exports.ldIndirectIVx(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 468..472
src/chip8.js on lines 474..478
src/chip8.js on lines 480..484
src/chip8.js on lines 486..490

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

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

      if (c === 0x1 && d === 0xe) {
        const x = b;
        if (logger) logger.log(`Fx1E - ADD I, Vx=${x.toString(16)}`);
        return module.exports.addIVx(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 468..472
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

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

      if (c === 0x0 && d === 0x7) {
        const x = b;
        if (logger) logger.log(`Fx07 - LD Vx, DT, Vx=${x.toString(16)}`);
        return module.exports.ldVxDT(chip, x);
      }
Severity: Major
Found in src/chip8.js and 5 other locations - About 2 hrs to fix
src/chip8.js on lines 468..472
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

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

      if (c === 0x3 && d === 0x3) {
        const x = b;
        if (logger) logger.log(`Fx33, Vx=${x.toString(16)}`);
        return module.exports.ldB(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 468..472
src/chip8.js on lines 474..478
src/chip8.js on lines 480..484
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

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