Conditions | 1 |
Paths | 1 |
Total Lines | 70 |
Lines | 0 |
Ratio | 0 % |
Changes | 1 | ||
Bugs | 0 | Features | 1 |
Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.
For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.
Commonly applied refactorings include:
If many parameters/temporary variables are present:
1 | import createEnhancer from '../enhancer-creator'; |
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3 | describe('createEnhancer can create enhancer', () => { |
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4 | describe('when input function', () => { |
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5 | it('output enhanced function with original name', () => { |
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6 | const orignal = () => {}; |
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7 | const enhancement = input => () => input(); |
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8 | const enhancer = createEnhancer(enhancement); |
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9 | const enhanced = enhancer(orignal); |
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10 | expect(enhanced.name).toBe('orignal'); |
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11 | }); |
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12 | |||
13 | it('output enhanced function invoking enhancement function and orignal function', () => { |
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14 | const enhancementSideEffect = jest.fn(); |
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15 | const orignal = jest.fn(); |
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16 | const enhancer = createEnhancer(input => () => { |
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17 | enhancementSideEffect(); |
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18 | return input(); |
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19 | }); |
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20 | const enhanced = enhancer(orignal); |
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21 | enhanced(); |
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22 | expect(orignal.mock.calls).toHaveLength(1); |
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23 | expect(enhancementSideEffect.mock.calls).toHaveLength(1); |
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24 | }); |
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25 | }); |
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26 | |||
27 | describe('when input function bundle', () => { |
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28 | it('output function bundle of functions name as method names', () => { |
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29 | const functionBundle = { |
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30 | methodA: () => {}, |
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31 | methodB: () => {}, |
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32 | }; |
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33 | const enhancer = createEnhancer(input => () => input()); |
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34 | const enhanced = enhancer(functionBundle); |
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35 | expect(enhanced.methodA.name).toBe('methodA'); |
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36 | expect(enhanced.methodB.name).toBe('methodB'); |
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37 | }); |
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38 | |||
39 | it('output function bundle of functions invoking enhancement function and origial functions', () => { |
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40 | const enhancementSideEffect = jest.fn(); |
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41 | const methodA = jest.fn(); |
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42 | const methodB = jest.fn(); |
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43 | const functionBundle = { |
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44 | methodA, |
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45 | methodB, |
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46 | }; |
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47 | const enhancer = createEnhancer(input => () => { |
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48 | enhancementSideEffect(); |
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49 | return input(); |
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50 | }); |
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51 | const enhanced = enhancer(functionBundle); |
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52 | enhanced.methodA(); |
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53 | expect(methodA.mock.calls).toHaveLength(1); |
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54 | expect(enhancementSideEffect.mock.calls).toHaveLength(1); |
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55 | enhanced.methodB(); |
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56 | expect(methodB.mock.calls).toHaveLength(1); |
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57 | expect(enhancementSideEffect.mock.calls).toHaveLength(2); |
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58 | }); |
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59 | }); |
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60 | |||
61 | it('when input is invalid throws error', () => { |
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62 | const enhancer = createEnhancer(input => () => input()); |
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63 | const doEnhanceStringInput = () => enhancer('test'); |
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64 | expect(doEnhanceStringInput).toThrowErrorMatchingSnapshot(); |
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65 | |||
66 | const doEnhanceInvalidObject = () => |
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67 | enhancer({ |
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68 | foo: 'bar', |
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69 | }); |
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70 | expect(doEnhanceInvalidObject).toThrowErrorMatchingSnapshot(); |
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71 | }); |
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72 | }); |
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73 |
This checks looks for references to variables that have not been declared. This is most likey a typographical error or a variable has been renamed.
To learn more about declaring variables in Javascript, see the MDN.