feat(data-point-codemods): Add codemod for changing PathReducer from $. to $

packages/data-point-codemods/README.md

@@ -38,6 +38,7 @@ data-point-codemods --help
 
 - ([codemod](transforms/reducer-args-acc-to-val-acc.js)) Refactor ReducerFunctions for value as first parameter eg. `(acc)` → `(input, acc)`. For more info please look at the [input](transforms/__testfixtures__/reducer-args-acc-to-val-acc.input.js)/[output](transforms/__testfixtures__/reducer-args-acc-to-val-acc.output.js) tests.
 
+- ([codemod](transforms/change-path-reducer-accessing-root-path.js)) Refactor PathReducers that access the root with `$.` to use `$`. For more info please look at the [input](transforms/__testfixtures__/change-path-reducer-accessing-root-path.input.js)/[output](transforms/__testfixtures__/change-path-reducer-accessing-root-path.output.js) tests.
 
 ## WARNING
 

packages/data-point-codemods/transforms/__testfixtures__/change-path-reducer-accessing-root-path-double-quote.input.js

@@ -0,0 +1,13 @@
+/* eslint-disable */
+/* eslint-disable prettier */
+
+// prettier-ignore
+const entities = {
+  'transform:a': `$.`,
+  'transform:b': `$. | foo | $.`,
+  'transform:c': `foo | bar | baz`,
+  'transform:d': "$.",
+  'transform:e': "$. | foo",
+  'transform:f': "$. | $. | $.",
+  'transform:g': "foo | bar | baz"
+}

packages/data-point-codemods/transforms/__testfixtures__/change-path-reducer-accessing-root-path-double-quote.output.js

@@ -0,0 +1,13 @@
+/* eslint-disable */
+/* eslint-disable prettier */
+
+// prettier-ignore
+const entities = {
+  'transform:a': `$`,
+  'transform:b': `$ | foo | $`,
+  'transform:c': `foo | bar | baz`,
+  'transform:d': "$",
+  'transform:e': "$ | foo",
+  'transform:f': "$ | $ | $",
+  'transform:g': "foo | bar | baz"
+}

packages/data-point-codemods/transforms/__testfixtures__/change-path-reducer-accessing-root-path-single-quote.input.js

@@ -0,0 +1,13 @@
+/* eslint-disable */
+/* eslint-disable prettier */
+
+// prettier-ignore
+const entities = {
+  'transform:a': `$.`,
+  'transform:b': `$. | foo | $.`,
+  'transform:c': `foo | bar | baz`,
+  'transform:d': '$.',
+  'transform:e': '$. | foo',
+  'transform:f': '$. | $. | $.',
+  'transform:g': 'foo | bar | baz'
+}

packages/data-point-codemods/transforms/__testfixtures__/change-path-reducer-accessing-root-path-single-quote.output.js

@@ -0,0 +1,13 @@
+/* eslint-disable */
+/* eslint-disable prettier */
+
+// prettier-ignore
+const entities = {
+  'transform:a': `$`,
+  'transform:b': `$ | foo | $`,
+  'transform:c': `foo | bar | baz`,
+  'transform:d': '$',
+  'transform:e': '$ | foo',
+  'transform:f': '$ | $ | $',
+  'transform:g': 'foo | bar | baz'
+}

packages/data-point-codemods/transforms/__tests__/change-path-reducer-accessing-root-path.test.js

@@ -0,0 +1,21 @@
+/* eslint-env jest */
+
+'use strict'
+
+const { defineTest } = require('jscodeshift/dist/testUtils')
+
+// single quote
+defineTest(
+  __dirname,
+  'change-path-reducer-accessing-root-path',
+  null,
+  'change-path-reducer-accessing-root-path-single-quote'
+)
+
+// double quote
+defineTest(
+  __dirname,
+  'change-path-reducer-accessing-root-path',
+  null,
+  'change-path-reducer-accessing-root-path-double-quote'
+)

packages/data-point-codemods/transforms/change-path-reducer-accessing-root-path.js

@@ -0,0 +1,62 @@
+module.exports = (file, api) => {
+  const j = api.jscodeshift
+  const rootPathWithDotRegex = /\$\.(\s|$)/g
+
+  const root = j(file.source)
+
+  function detectQuoteStyle (j, root) {
+    let detectedQuoting = 'single'
+
+    root
+      .find(j.Literal, {
+        value: v => typeof v === 'string',
+        raw: v => typeof v === 'string'
+      })
+      .forEach(p => {
+        // The raw value is from the original babel source
+        if (p.value.raw[0] === "'") {
+          detectedQuoting = 'single'
+        }
+
+        if (p.value.raw[0] === '"') {
+          detectedQuoting = 'double'
+        }
+      })
+
+    return detectedQuoting
+  }
+
+  // transforms a string from '$. | $. | $.' -> '$ | $ | $'
+  function transformLiteral (node) {
+    const originalValue = node.value.value
+    if (rootPathWithDotRegex.test(originalValue)) {
+      node.value.value = node.value.value.replace(rootPathWithDotRegex, '$$$1')
+    }
+  }
+
+  // transforms a template literal from `$. | $. | $.` -> `$ | $ | $`
+  function transformTemplateElement (node) {
+    const originalValue = node.value.value.raw
+    if (rootPathWithDotRegex.test(originalValue)) {
+      node.value.value.raw = node.value.value.raw.replace(
+        rootPathWithDotRegex,
+        '$$$1'
+      )
+    }
+  }
+
+  function refactorReducerMatches (nodeType, transform) {
+    root.find(nodeType).forEach(transform)
+  }
+
+  refactorReducerMatches(j.Literal, transformLiteral)
+  refactorReducerMatches(j.TemplateElement, transformTemplateElement)
+
+  // As Recast is not preserving original quoting, we try to detect it,
+  // and default to something sane.
+  // See https://github.com/benjamn/recast/issues/171
+  // and https://github.com/facebook/jscodeshift/issues/143
+  // credit to @skovhus: https://github.com/avajs/ava-codemods/pull/28
+  const quote = detectQuoteStyle(j, root)
+  return root.toSource({ quote })
+}