feat: add remove subroutine

gajus · gajus · commit 989b53e88a01 · 2018-05-08T12:57:41.000+01:00
diff --git a/README.md b/README.md
@@ -60,6 +60,7 @@ Have you got suggestions for improvement? [I am all ears](https://github.com/gaj
     * [`nextUntil` subroutine](#nextuntil-subroutine)
     * [`select` subroutine](#select-subroutine)
       * [Quantifier expression](#quantifier-expression)
+    * [`remove` subroutine](#remove-subroutine)
     * [`read` subroutine](#read-subroutine)
     * [`test` subroutine](#test-subroutine)
   * [User-defined subroutines](#user-defined-subroutines)
@@ -229,6 +230,27 @@ x('select .foo {0,}[0]');
 
 ```
 
+#### `remove` subroutine
+
+`remove` subroutine is used to remove elements from the document using an [evaluator](#evaluators).
+
+`remove` subroutine accepts the same parameters as the `select` subroutine.
+
+The result of `remove` subroutine is the input of the subroutine, i.e. previous `select` subroutine result.
+
+|Parameter name|Description|Default|
+|---|---|---|
+|CSS selector|CSS selector used to select an element.|N/A|
+|Quantifier expression|A [quantifier expression](#quantifier-expression) is used to control the expected result length.|See [quantifier expression](#quantifier-expression).|
+
+Examples:
+
+```js
+// Returns 'bar'.
+x('select .foo | remove span | read property textContent', `<div class='foo'>bar<span>baz</span></div>`);
+
+```
+
 #### `read` subroutine
 
 `read` is used to extract value from the matching element using an [evaluator](#evaluators).
diff --git a/package.json b/package.json
@@ -32,6 +32,7 @@
     "flow-bin": "^0.57.3",
     "flow-copy-source": "^1.3.0",
     "husky": "^0.14.3",
+    "lodash": "^4.17.10",
     "nyc": "^11.2.1",
     "semantic-release": "^8.2.0",
     "sinon": "^4.0.2",
diff --git a/src/evaluators/browserEvaluator.js b/src/evaluators/browserEvaluator.js
@@ -44,7 +44,12 @@ export default (): EvaluatorType => {
 
   // eslint-disable-next-line no-unused-vars
   const nextUntil = (node, selector, filter) => {
-    throw new Error('Not implemented.');
+    throw new Error('Unimplemented.');
+  };
+
+  // eslint-disable-next-line no-unused-vars
+  const remove = (node) => {
+    throw new Error('Unimplemented.');
   };
 
   return {
@@ -53,6 +58,7 @@ export default (): EvaluatorType => {
     isElement,
     nextUntil,
     parseDocument,
-    querySelectorAll
+    querySelectorAll,
+    remove
   };
 };
diff --git a/src/evaluators/cheerioEvaluator.js b/src/evaluators/cheerioEvaluator.js
@@ -71,12 +71,17 @@ export default (): EvaluatorType => {
       });
   };
 
+  const remove = (node) => {
+    node.remove();
+  };
+
   return {
     getAttributeValue,
     getPropertyValue,
     isElement,
     nextUntil,
     parseDocument,
-    querySelectorAll
+    querySelectorAll,
+    remove
   };
 };
diff --git a/src/index.js b/src/index.js
@@ -20,6 +20,7 @@ import {
 import {
   nextUntilSubroutine,
   readSubroutine,
+  removeSubroutine,
   selectSubroutine,
   testSubroutine
 } from './subroutines';
@@ -46,6 +47,7 @@ export {
 const builtInSubroutines = {
   nextUntil: nextUntilSubroutine,
   read: readSubroutine,
+  remove: removeSubroutine,
   select: selectSubroutine,
   test: testSubroutine
 };
diff --git a/src/subroutines/index.js b/src/subroutines/index.js
@@ -2,5 +2,6 @@
 
 export {default as nextUntilSubroutine} from './nextUntilSubroutine';
 export {default as readSubroutine} from './readSubroutine';
+export {default as removeSubroutine} from './removeSubroutine';
 export {default as selectSubroutine} from './selectSubroutine';
 export {default as testSubroutine} from './testSubroutine';
diff --git a/src/subroutines/removeSubroutine.js b/src/subroutines/removeSubroutine.js
@@ -0,0 +1,32 @@
+// @flow
+
+import {
+  FinalResultSentinel
+} from 'pianola';
+import {
+  createDebug
+} from '../utilities';
+import type {
+  SubroutineType
+} from '../types';
+import selectSubroutine from './selectSubroutine';
+
+const debug = createDebug('subroutine:remove');
+
+const removeSubroutine: SubroutineType = (subject, [cssSelector, quantifierExpression], {evaluator}) => {
+  debug('selecting "%s" for removal', cssSelector);
+
+  const matches = selectSubroutine(subject, [cssSelector, quantifierExpression], {evaluator});
+
+  if (Array.isArray(matches)) {
+    for (const match of matches) {
+      evaluator.remove(match);
+    }
+  } else if (!(matches instanceof FinalResultSentinel)) {
+    evaluator.remove(matches);
+  }
+
+  return subject;
+};
+
+export default removeSubroutine;
diff --git a/src/types.js b/src/types.js
@@ -12,7 +12,8 @@ export type EvaluatorType = {|
   +isElement: (maybeElement: mixed) => boolean,
   +nextUntil: (element: ElementType, selector: string, filter?: string) => $ReadOnlyArray<ElementType>,
   +parseDocument: (subject: string) => ElementType,
-  +querySelectorAll: (element: ElementType, selector: string) => $ReadOnlyArray<ElementType>
+  +querySelectorAll: (element: ElementType, selector: string) => $ReadOnlyArray<ElementType>,
+  +remove: (element: ElementType) => void
 |};
 
 export type SubroutineType = (subject: mixed, parameters: $ReadOnlyArray<string>, bindle: BindleType) => mixed;
diff --git a/test/surgeon/queries/remove.js b/test/surgeon/queries/remove.js
@@ -0,0 +1,92 @@
+// @flow
+
+import test from 'ava';
+import {
+  trim
+} from 'lodash';
+import surgeon, {
+  SelectSubroutineUnexpectedResultCountError
+} from '../../../src';
+import type {
+  DenormalizedQueryType
+} from '../../../src/types';
+
+test('removes a single element', (t): void => {
+  const x = surgeon();
+
+  const subject = `
+    <div class="foo">
+      <div class="bar"></div>
+      <div class="baz"></div>
+    </div>
+  `;
+
+  const query: DenormalizedQueryType = 'select .foo | remove .bar | read property innerHTML';
+
+  t.true(trim(x(query, subject)) === '<div class="baz"></div>');
+});
+
+test('removes nothing if no nodes are matched {0,1}', (t) => {
+  const x = surgeon();
+
+  const subject = `
+    <div class="foo">
+      <div class="baz"></div>
+    </div>
+  `;
+
+  const query: DenormalizedQueryType = 'select .foo | remove .bar {0,1} | read property innerHTML';
+
+  t.true(trim(x(query, subject)) === '<div class="baz"></div>');
+});
+
+test('removes multiple elements {0,}', (t) => {
+  const x = surgeon();
+
+  const subject = `
+    <div class="foo">
+      <div class="bar"></div>
+      <div class="baz"></div>
+      <div class="baz"></div>
+      <div class="baz"></div>
+    </div>
+  `;
+
+  const query: DenormalizedQueryType = 'select .foo | remove .baz {0,} | read property innerHTML';
+
+  t.true(trim(x(query, subject)) === '<div class="bar"></div>');
+});
+
+test('throws error if no nodes are matched', (t): void => {
+  const x = surgeon();
+
+  const subject = `
+    <div class="foo">
+      <div class="bar"></div>
+      <div class="baz"></div>
+    </div>
+  `;
+
+  const query: DenormalizedQueryType = 'select .foo | remove .qux | read property innerHTML';
+
+  t.throws(() => {
+    x(query, subject);
+  }, SelectSubroutineUnexpectedResultCountError);
+});
+
+test('throws error if more than one node is matched', (t): void => {
+  const x = surgeon();
+
+  const subject = `
+    <div class="foo">
+      <div class="bar"></div>
+      <div class="bar"></div>
+    </div>
+  `;
+
+  const query: DenormalizedQueryType = 'select .foo | remove .bar | read property innerHTML';
+
+  t.throws(() => {
+    x(query, subject);
+  }, SelectSubroutineUnexpectedResultCountError);
+});
