Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like Parser often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Parser, and based on these observations, apply Extract Interface, too.
1 | <?php |
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34 | class Parser |
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35 | { |
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36 | private $lexer; |
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37 | private $input; |
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38 | private $file; |
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39 | private $tags = array(); |
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40 | private $languageSpecifierLine; |
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41 | |||
42 | /** |
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43 | * Initializes parser. |
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44 | * |
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45 | * @param Lexer $lexer Lexer instance |
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46 | */ |
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47 | 55 | public function __construct(Lexer $lexer) |
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51 | |||
52 | /** |
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53 | * Parses input & returns features array. |
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54 | * |
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55 | * @param string $input Gherkin string document |
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56 | * @param string $file File name |
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57 | * |
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58 | * @return FeatureNode|null |
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59 | * |
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60 | * @throws ParserException |
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61 | */ |
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62 | 53 | public function parse($input, $file = null) |
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63 | { |
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64 | 53 | $this->languageSpecifierLine = null; |
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65 | 53 | $this->input = $input; |
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66 | 53 | $this->file = $file; |
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67 | 53 | $this->tags = array(); |
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68 | |||
69 | try { |
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70 | 53 | $this->lexer->analyse($this->input, 'en'); |
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71 | 53 | } catch (LexerException $e) { |
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72 | throw new ParserException( |
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73 | sprintf('Lexer exception "%s" thrown for file %s', $e->getMessage(), $file), |
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74 | 0, |
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75 | $e |
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76 | ); |
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77 | } |
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78 | |||
79 | 53 | $feature = null; |
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80 | 53 | while ('EOS' !== ($predicted = $this->predictTokenType())) { |
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81 | 53 | $node = $this->parseExpression(); |
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82 | |||
83 | 45 | if (null === $node || "\n" === $node) { |
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84 | 3 | continue; |
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85 | } |
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86 | |||
87 | 44 | if (!$feature && $node instanceof FeatureNode) { |
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88 | 44 | $feature = $node; |
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89 | 44 | continue; |
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90 | } |
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91 | |||
92 | if ($feature && $node instanceof FeatureNode) { |
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93 | throw new ParserException(sprintf( |
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94 | 'Only one feature is allowed per feature file. But %s got multiple.', |
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95 | $this->file |
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96 | )); |
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97 | } |
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98 | |||
99 | if (is_string($node)) { |
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100 | throw new ParserException(sprintf( |
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101 | 'Expected Feature, but got text: "%s"%s', |
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102 | $node, |
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103 | $this->file ? ' in file: ' . $this->file : '' |
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104 | )); |
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105 | } |
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106 | |||
107 | if (!$node instanceof FeatureNode) { |
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108 | throw new ParserException(sprintf( |
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109 | 'Expected Feature, but got %s on line: %d%s', |
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110 | $node->getKeyword(), |
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111 | $node->getLine(), |
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112 | $this->file ? ' in file: ' . $this->file : '' |
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113 | )); |
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114 | } |
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115 | } |
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116 | |||
117 | 44 | return $feature; |
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118 | } |
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119 | |||
120 | /** |
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121 | * Returns next token if it's type equals to expected. |
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122 | * |
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123 | * @param string $type Token type |
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124 | * |
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125 | * @return array |
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126 | * |
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127 | * @throws Exception\ParserException |
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128 | */ |
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129 | 53 | protected function expectTokenType($type) |
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130 | { |
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131 | 53 | $types = (array) $type; |
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132 | 53 | if (in_array($this->predictTokenType(), $types)) { |
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133 | 53 | return $this->lexer->getAdvancedToken(); |
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134 | } |
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135 | |||
136 | 1 | $token = $this->lexer->predictToken(); |
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137 | |||
138 | 1 | throw new ParserException(sprintf( |
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139 | 1 | 'Expected %s token, but got %s on line: %d%s', |
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140 | 1 | implode(' or ', $types), |
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141 | 1 | $this->predictTokenType(), |
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142 | 1 | $token['line'], |
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143 | 1 | $this->file ? ' in file: ' . $this->file : '' |
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144 | 1 | )); |
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145 | } |
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146 | |||
147 | /** |
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148 | * Returns next token if it's type equals to expected. |
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149 | * |
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150 | * @param string $type Token type |
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151 | * |
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152 | * @return null|array |
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153 | */ |
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154 | 35 | protected function acceptTokenType($type) |
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162 | |||
163 | /** |
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164 | * Returns next token type without real input reading (prediction). |
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165 | * |
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166 | * @return string |
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167 | */ |
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168 | 53 | protected function predictTokenType() |
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174 | |||
175 | /** |
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176 | * Parses current expression & returns Node. |
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177 | * |
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178 | * @return string|FeatureNode|BackgroundNode|ScenarioNode|OutlineNode|TableNode|StepNode |
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179 | * |
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180 | * @throws ParserException |
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181 | */ |
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182 | 53 | protected function parseExpression() |
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217 | |||
218 | /** |
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219 | * Parses feature token & returns it's node. |
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220 | * |
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221 | * @return FeatureNode |
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222 | * |
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223 | * @throws ParserException |
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224 | */ |
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225 | 52 | protected function parseFeature() |
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290 | |||
291 | /** |
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292 | * Parses background token & returns it's node. |
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293 | * |
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294 | * @return BackgroundNode |
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295 | * |
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296 | * @throws ParserException |
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297 | */ |
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298 | 10 | protected function parseBackground() |
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299 | { |
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300 | 10 | $token = $this->expectTokenType('Background'); |
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301 | |||
302 | 10 | $title = trim($token['value']); |
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303 | 10 | $keyword = $token['keyword']; |
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304 | 10 | $line = $token['line']; |
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305 | |||
306 | 10 | if (count($this->popTags())) { |
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307 | 1 | throw new ParserException(sprintf( |
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308 | 1 | 'Background can not be tagged, but it is on line: %d%s', |
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309 | 1 | $line, |
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310 | 1 | $this->file ? ' in file: ' . $this->file : '' |
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311 | 1 | )); |
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312 | } |
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313 | |||
314 | // Parse description and steps |
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315 | 9 | $steps = array(); |
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316 | 9 | $allowedTokenTypes = array('Step', 'Newline', 'Text', 'Comment'); |
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317 | 9 | while (in_array($this->predictTokenType(), $allowedTokenTypes)) { |
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318 | 9 | $node = $this->parseExpression(); |
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319 | |||
320 | 9 | if ($node instanceof StepNode) { |
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321 | 8 | $steps[] = $this->normalizeStepNodeKeywordType($node, $steps); |
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322 | 8 | continue; |
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323 | } |
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324 | |||
325 | 4 | View Code Duplication | if (!count($steps) && is_string($node)) { |
326 | 4 | $text = preg_replace('/^\s{0,' . ($token['indent'] + 2) . '}|\s*$/', '', $node); |
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327 | 4 | $title .= "\n" . $text; |
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328 | 4 | continue; |
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329 | } |
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330 | |||
331 | if ("\n" === $node) { |
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332 | continue; |
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333 | } |
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334 | |||
335 | View Code Duplication | if (is_string($node)) { |
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336 | throw new ParserException(sprintf( |
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337 | 'Expected Step, but got text: "%s"%s', |
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338 | $node, |
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339 | $this->file ? ' in file: ' . $this->file : '' |
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340 | )); |
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341 | } |
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342 | |||
343 | View Code Duplication | if (!$node instanceof StepNode) { |
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344 | throw new ParserException(sprintf( |
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345 | 'Expected Step, but got %s on line: %d%s', |
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346 | $node->getNodeType(), |
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347 | $node->getLine(), |
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348 | $this->file ? ' in file: ' . $this->file : '' |
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349 | )); |
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350 | } |
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351 | } |
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352 | |||
353 | 9 | return new BackgroundNode(rtrim($title) ?: null, $steps, $keyword, $line); |
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354 | } |
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355 | |||
356 | /** |
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357 | * Parses scenario token & returns it's node. |
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358 | * |
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359 | * @return ScenarioNode |
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360 | * |
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361 | * @throws ParserException |
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362 | */ |
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363 | 39 | protected function parseScenario() |
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412 | |||
413 | /** |
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414 | * Parses scenario outline token & returns it's node. |
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415 | * |
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416 | * @return OutlineNode |
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417 | * |
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418 | * @throws ParserException |
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419 | */ |
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420 | 17 | protected function parseOutline() |
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484 | |||
485 | /** |
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486 | * Parses step token & returns it's node. |
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487 | * |
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488 | * @return StepNode |
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489 | */ |
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490 | 40 | protected function parseStep() |
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515 | |||
516 | /** |
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517 | * Parses examples table node. |
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518 | * |
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519 | * @return ExampleTableNode |
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520 | */ |
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521 | 16 | protected function parseExamples() |
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529 | |||
530 | /** |
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531 | * Parses table token & returns it's node. |
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532 | * |
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533 | * @return TableNode |
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534 | */ |
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535 | 3 | protected function parseTable() |
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536 | { |
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537 | 3 | return new TableNode($this->parseTableRows()); |
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538 | } |
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539 | |||
540 | /** |
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541 | * Parses PyString token & returns it's node. |
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542 | * |
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543 | * @return PyStringNode |
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544 | */ |
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545 | 10 | protected function parsePyString() |
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546 | { |
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547 | 10 | $token = $this->expectTokenType('PyStringOp'); |
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548 | |||
549 | 10 | $line = $token['line']; |
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550 | |||
551 | 10 | $strings = array(); |
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552 | 10 | while ('PyStringOp' !== ($predicted = $this->predictTokenType()) && 'Text' === $predicted) { |
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553 | 10 | $token = $this->expectTokenType('Text'); |
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554 | |||
555 | 10 | $strings[] = $token['value']; |
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556 | 10 | } |
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557 | |||
558 | 10 | $this->expectTokenType('PyStringOp'); |
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559 | |||
560 | 9 | return new PyStringNode($strings, $line); |
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561 | } |
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562 | |||
563 | /** |
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564 | * Parses tags. |
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565 | * |
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566 | * @return BackgroundNode|FeatureNode|OutlineNode|ScenarioNode|StepNode|TableNode|string |
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567 | */ |
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568 | 5 | protected function parseTags() |
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575 | |||
576 | /** |
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577 | * Returns current set of tags and clears tag buffer. |
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578 | * |
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579 | * @return array |
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580 | */ |
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581 | 52 | protected function popTags() |
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588 | |||
589 | /** |
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590 | * Parses next text line & returns it. |
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591 | * |
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592 | * @return string |
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593 | */ |
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594 | 29 | protected function parseText() |
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600 | |||
601 | /** |
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602 | * Parses next newline & returns \n. |
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603 | * |
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604 | * @return string |
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605 | */ |
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606 | 45 | protected function parseNewline() |
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612 | |||
613 | /** |
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614 | * Parses next comment token & returns it's string content. |
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615 | * |
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616 | * @return BackgroundNode|FeatureNode|OutlineNode|ScenarioNode|StepNode|TableNode|string |
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617 | */ |
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618 | 8 | protected function parseComment() |
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624 | |||
625 | /** |
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626 | * Parses language block and updates lexer configuration based on it. |
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627 | * |
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628 | * @return BackgroundNode|FeatureNode|OutlineNode|ScenarioNode|StepNode|TableNode|string |
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629 | * |
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630 | * @throws ParserException |
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631 | */ |
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632 | 9 | protected function parseLanguage() |
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633 | { |
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634 | 9 | $token = $this->expectTokenType('Language'); |
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635 | |||
636 | 9 | if (null === $this->languageSpecifierLine) { |
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637 | 9 | $this->lexer->analyse($this->input, $token['value']); |
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638 | 9 | $this->languageSpecifierLine = $token['line']; |
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639 | 9 | } elseif ($token['line'] !== $this->languageSpecifierLine) { |
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640 | 1 | throw new ParserException(sprintf( |
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641 | 1 | 'Ambiguous language specifiers on lines: %d and %d%s', |
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642 | 1 | $this->languageSpecifierLine, |
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643 | 1 | $token['line'], |
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644 | 1 | $this->file ? ' in file: ' . $this->file : '' |
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645 | 1 | )); |
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646 | } |
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647 | |||
648 | 9 | return $this->parseExpression(); |
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649 | } |
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650 | |||
651 | /** |
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652 | * Parses the rows of a table |
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653 | * |
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654 | * @return string[][] |
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655 | */ |
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656 | 17 | private function parseTableRows() |
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657 | { |
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658 | 17 | $table = array(); |
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659 | 17 | while (in_array($predicted = $this->predictTokenType(), array('TableRow', 'Newline', 'Comment'))) { |
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660 | 17 | if ('Comment' === $predicted || 'Newline' === $predicted) { |
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661 | 11 | $this->acceptTokenType($predicted); |
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662 | 11 | continue; |
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663 | } |
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664 | |||
665 | 17 | $token = $this->expectTokenType('TableRow'); |
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666 | |||
667 | 17 | $table[$token['line']] = $token['columns']; |
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668 | 17 | } |
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669 | |||
670 | 17 | return $table; |
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671 | } |
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672 | |||
673 | /** |
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674 | * Changes step node type for types But, And to type of previous step if it exists else sets to Given |
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675 | * |
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676 | * @param StepNode $node |
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677 | * @param StepNode[] $steps |
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678 | * @return StepNode |
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679 | */ |
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680 | 39 | private function normalizeStepNodeKeywordType(StepNode $node, array $steps = array()) |
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699 | } |
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700 |
It seems like the method you are trying to call exists only in some of the possible types.
Let’s take a look at an example:
Available Fixes
Add an additional type-check:
Only allow a single type to be passed if the variable comes from a parameter: