Feature: importOrderMergeDuplicateImports

README.md

@@ -86,21 +86,27 @@ yarn add --dev @ianvs/prettier-plugin-sort-imports
 
 ## Usage
 
-Add an order in prettier config file.
+Add your preferred settings in your prettier config file.
 
-```ecmascript 6
+```javascript
 module.exports = {
   "printWidth": 80,
   "tabWidth": 4,
   "trailingComma": "all",
   "singleQuote": true,
   "semi": true,
   "importOrder": ["^@core/(.*)$", "^@server/(.*)$", "^@ui/(.*)$", "^[./]"],
+  "importOrderBuiltinModulesToTop": true,
+  "importOrderCaseInsensitive": true,
+  "importOrderParserPlugins": ["typescript", "jsx", "decorators-legacy"],
+  "importOrderMergeDuplicateImports": true,
   "importOrderSeparation": true,
-  "importOrderSortSpecifiers": true
+  "importOrderSortSpecifiers": true,
 }
 ```
 
+_Note: all flags are off by default, so explore your options [below](#apis)_
+
 ### APIs
 
 #### Prevent imports from being sorted
@@ -204,6 +210,14 @@ import ExamplesList from './ExamplesList';
 import ExampleView from './ExampleView';
 ```
 
+#### `importOrderMergeDuplicateImports`
+
+**type**: `boolean`
+
+**default value:** `false`
+
+A boolean value to enable or disable multiple import statements referencing the same source. Not all patterns can be merged! Notably: `import type …` will not be converted to `import {type …` or vice-versa.
+
 #### `importOrderParserPlugins`
 
 **type**: `Array<string>`

docs/TROUBLESHOOTING.md

@@ -7,7 +7,7 @@
 You can define the RegEx in the `importOrder`. For
 example if you want to sort the following imports:
 
-```ecmascript 6
+```javascript
 import React from 'react';
 import classnames from 'classnames';
 import z from '@server/z';
@@ -20,7 +20,7 @@ import q from '@ui/q';
 then the `importOrder` would be `["^@ui/(.*)$","^@server/(.*)$", '^[./]']`.
 Now, the final output would be as follows:
 
-```ecmascript 6
+```javascript
 import classnames from 'classnames';
 import React from 'react';
 import p from '@ui/p';
@@ -35,7 +35,7 @@ import s from './';
 You can define the `<THIRD_PARTY_MODULES>` special word in the `importOrder`. For example above, the `importOrder` would be like `["^@ui/(.*)$", "^@server/(.*)$", "<THIRD_PARTY_MODULES>", '^[./]']`.
 Now, the final output would be as follows:
 
-```ecmascript 6
+```javascript
 import p from '@ui/p';
 import q from '@ui/q';
 import a from '@server/a';

src/constants.ts

@@ -11,6 +11,17 @@ export const newLineCharacters = '\n\n';
 export const chunkTypeUnsortable = 'unsortable';
 export const chunkTypeOther = 'other';
 
+/** import Thing from ... or import {Thing} from ... */
+export const importFlavorRegular = 'regular';
+/** import type {} from ...  */
+export const importFlavorType = 'type';
+export const importFlavorSideEffect = 'side-effect';
+export const importFlavorIgnore = 'prettier-ignore';
+export const mergeableImportFlavors = [
+    importFlavorRegular,
+    importFlavorType,
+] as const;
+
 /*
  * Used to mark the position between RegExps,
  * where the not matched imports should be placed

src/index.ts

@@ -1,10 +1,24 @@
+import type { RequiredOptions as PrettierRequiredOptions } from 'prettier';
 import { parsers as babelParsers } from 'prettier/parser-babel';
 import { parsers as flowParsers } from 'prettier/parser-flow';
 import { parsers as typescriptParsers } from 'prettier/parser-typescript';
 
 import { preprocessor } from './preprocessor';
+import type { PrettierOptions } from './types';
 
-const options = {
+// Not sure what the type from Prettier should be, but this is a good enough start.
+interface PrettierOptionSchema {
+    type: string;
+    category: 'Global';
+    array?: boolean;
+    default: unknown;
+    description: string;
+}
+
+const options: Record<
+    Exclude<keyof PrettierOptions, keyof PrettierRequiredOptions>,
+    PrettierOptionSchema
+> = {
     importOrder: {
         type: 'path',
         category: 'Global',
@@ -52,6 +66,12 @@ const options = {
         default: false,
         description: 'Should node-builtins be hoisted to the top?',
     },
+    importOrderMergeDuplicateImports: {
+        type: 'boolean',
+        category: 'Global',
+        default: false,
+        description: 'Should duplicate imports be merged?',
+    },
 };
 
 module.exports = {

src/preprocessor.ts

@@ -11,11 +11,12 @@ export function preprocessor(code: string, options: PrettierOptions): string {
     const {
         importOrderParserPlugins,
         importOrder,
+        importOrderBuiltinModulesToTop,
         importOrderCaseInsensitive,
-        importOrderSeparation,
         importOrderGroupNamespaceSpecifiers,
+        importOrderMergeDuplicateImports,
+        importOrderSeparation,
         importOrderSortSpecifiers,
-        importOrderBuiltinModulesToTop,
     } = options;
 
     const importNodes: ImportDeclaration[] = [];
@@ -40,19 +41,26 @@ export function preprocessor(code: string, options: PrettierOptions): string {
         },
     });
 
-    // short-circuit if there are no import declaration
+    // short-circuit if there are no import declarations
     if (importNodes.length === 0) {
         return code;
     }
 
-    const allImports = getSortedNodes(importNodes, {
+    const remainingImports = getSortedNodes(importNodes, {
         importOrder,
+        importOrderBuiltinModulesToTop,
         importOrderCaseInsensitive,
-        importOrderSeparation,
         importOrderGroupNamespaceSpecifiers,
+        importOrderMergeDuplicateImports,
+        importOrderSeparation,
         importOrderSortSpecifiers,
-        importOrderBuiltinModulesToTop,
     });
 
-    return getCodeFromAst(allImports, code, directives, interpreter);
+    return getCodeFromAst({
+        nodes: remainingImports,
+        importNodes,
+        originalCode: code,
+        directives,
+        interpreter,
+    });
 }

src/types.ts

@@ -5,11 +5,12 @@ export interface PrettierOptions extends RequiredOptions {
     importOrder: string[];
     importOrderCaseInsensitive: boolean;
     importOrderBuiltinModulesToTop: boolean;
-    // should be of type ParserPlugin from '@babel/parser' but prettier does not support nested arrays in options
-    importOrderParserPlugins: string[];
-    importOrderSeparation: boolean;
     importOrderGroupNamespaceSpecifiers: boolean;
+    importOrderMergeDuplicateImports: boolean;
+    importOrderSeparation: boolean;
     importOrderSortSpecifiers: boolean;
+    // should be of type ParserPlugin from '@babel/parser' but prettier does not support nested arrays in options
+    importOrderParserPlugins: string[];
 }
 
 export interface ImportChunk {
@@ -27,10 +28,17 @@ export type GetSortedNodes = (
         | 'importOrder'
         | 'importOrderBuiltinModulesToTop'
         | 'importOrderCaseInsensitive'
-        | 'importOrderSeparation'
         | 'importOrderGroupNamespaceSpecifiers'
+        | 'importOrderMergeDuplicateImports'
+        | 'importOrderSeparation'
         | 'importOrderSortSpecifiers'
     >,
 ) => ImportOrLine[];
 
 export type GetChunkTypeOfNode = (node: ImportDeclaration) => string;
+
+export type GetImportFlavorOfNode = (node: ImportDeclaration) => string;
+
+export type MergeNodesWithMatchingImportFlavors = (
+    nodes: ImportDeclaration[],
+) => ImportDeclaration[];

src/utils/__tests__/get-all-comments-from-nodes.spec.ts

@@ -10,11 +10,12 @@ const getSortedImportNodes = (code: string, options?: ParserOptions) => {
 
     return getSortedNodes(importNodes, {
         importOrder: [],
+        importOrderBuiltinModulesToTop: false,
         importOrderCaseInsensitive: false,
-        importOrderSeparation: false,
         importOrderGroupNamespaceSpecifiers: false,
+        importOrderMergeDuplicateImports: false,
+        importOrderSeparation: false,
         importOrderSortSpecifiers: false,
-        importOrderBuiltinModulesToTop: false,
     });
 };
 

src/utils/__tests__/get-code-from-ast.spec.ts

@@ -4,7 +4,7 @@ import { getCodeFromAst } from '../get-code-from-ast';
 import { getImportNodes } from '../get-import-nodes';
 import { getSortedNodes } from '../get-sorted-nodes';
 
-test('it sorts imports correctly', () => {
+it('sorts imports correctly', () => {
     const code = `// first comment
 // second comment
 import z from 'z';
@@ -17,13 +17,18 @@ import a from 'a';
     const importNodes = getImportNodes(code);
     const sortedNodes = getSortedNodes(importNodes, {
         importOrder: [],
+        importOrderBuiltinModulesToTop: false,
         importOrderCaseInsensitive: false,
-        importOrderSeparation: false,
         importOrderGroupNamespaceSpecifiers: false,
+        importOrderMergeDuplicateImports: false,
+        importOrderSeparation: false,
         importOrderSortSpecifiers: false,
-        importOrderBuiltinModulesToTop: false,
     });
-    const formatted = getCodeFromAst(sortedNodes, code, [], undefined);
+    const formatted = getCodeFromAst({
+        nodes: sortedNodes,
+        originalCode: code,
+        directives: [],
+    });
     expect(format(formatted, { parser: 'babel' })).toEqual(
         `// first comment
 // second comment
@@ -36,3 +41,43 @@ import z from "z";
 `,
     );
 });
+
+it('merges duplicate imports correctly', () => {
+    const code = `// first comment
+// second comment
+import z from 'z';
+import c from 'c';
+import g from 'g';
+import t from 't';
+import k from 'k';
+import a from 'a';
+import {b} from 'a';
+`;
+    const importNodes = getImportNodes(code);
+    const sortedNodes = getSortedNodes(importNodes, {
+        importOrder: [],
+        importOrderBuiltinModulesToTop: false,
+        importOrderCaseInsensitive: false,
+        importOrderGroupNamespaceSpecifiers: false,
+        importOrderMergeDuplicateImports: true,
+        importOrderSeparation: false,
+        importOrderSortSpecifiers: false,
+    });
+    const formatted = getCodeFromAst({
+        nodes: sortedNodes,
+        importNodes,
+        originalCode: code,
+        directives: [],
+    });
+    expect(format(formatted, { parser: 'babel' })).toEqual(
+        `// first comment
+// second comment
+import a, { b } from "a";
+import c from "c";
+import g from "g";
+import k from "k";
+import t from "t";
+import z from "z";
+`,
+    );
+});

src/utils/__tests__/get-import-flavor-of-node.spec.ts

@@ -0,0 +1,32 @@
+import { getImportFlavorOfNode } from '../get-import-flavor-of-node';
+import { getImportNodes } from '../get-import-nodes';
+
+it('should correctly classify a bunch of import expressions', () => {
+    expect(
+        getImportNodes(
+            `
+import "./side-effects";
+import { a } from "a";
+import type { b } from "b";
+import { type C } from "c";
+import D from "d";
+
+import e = require("e"); // Doesn't count as import
+const f = require("f"); // Doesn't count as import
+
+// prettier-ignore
+import { g } from "g";
+`,
+            { plugins: ['typescript'] },
+        ).map((node) => getImportFlavorOfNode(node)),
+    ).toMatchInlineSnapshot(`
+        Array [
+          "side-effect",
+          "regular",
+          "type",
+          "regular",
+          "regular",
+          "prettier-ignore",
+        ]
+    `);
+});