Sort exports (#55)

.eslintrc.js

@@ -15,6 +15,8 @@ module.exports = {
   env: { es6: true, node: true },
   rules: {
     "arrow-body-style": warn,
+    "default-case": error,
+    "default-case-last": warn,
     "dot-notation": warn,
     "no-caller": error,
     "no-console": warn,

examples/.eslintrc.js

@@ -13,14 +13,17 @@ module.exports = {
   },
   env: { es6: true },
   rules: {
-    // The actual rule name is "simple-import-sort/sort", but for technical
-    // reasons it’s just called "sort" within the examples of this repo.
-    // "simple-import-sort/sort": "error",
-    sort: "error",
+    // The actual rule names are "simple-import-sort/imports" and
+    // "simple-import-sort/exports", but for technical reasons they’re called
+    // just "imports" and "exports" within the examples of this repo.
+    // "simple-import-sort/imports": "error",
+    // "simple-import-sort/exports": "error",
+    imports: "error",
+    exports: "error",
   },
   overrides: [
     {
-      // This file only enables the “sort” rule from this plugin. After
+      // This file only enables the “imports” rule from this plugin. After
       // autofixing, there might be some oddly placed spaces.
       files: ["1.spaces.just-sort.js"],
     },
@@ -65,7 +68,7 @@ module.exports = {
     {
       files: ["groups.custom.js"],
       rules: {
-        sort: [
+        imports: [
           "error",
           {
             groups: [
@@ -94,7 +97,7 @@ module.exports = {
     {
       files: ["groups.no-blank-lines.js"],
       rules: {
-        sort: [
+        imports: [
           "error",
           {
             // The default grouping, but with no blank lines.
@@ -106,7 +109,7 @@ module.exports = {
     {
       files: ["groups.default-reverse.js"],
       rules: {
-        sort: [
+        imports: [
           "error",
           {
             // The default grouping, but in reverse.
@@ -118,7 +121,7 @@ module.exports = {
     {
       files: ["groups.none.js"],
       rules: {
-        sort: [
+        imports: [
           "error",
           {
             // No grouping, only alphabetical sorting.

examples/ignore.js

@@ -7,14 +7,14 @@ import "a";
 separator();
 
 // You can also disable sorting for a whole chunk. The actual rule name is
-// "simple-import-sort/sort", but for technical reasons it’s just called "sort"
-// within the examples of this repo.
-// For copying: eslint-disable-next-line simple-import-sort/sort
-// eslint-disable-next-line sort
+// "simple-import-sort/imports", but for technical reasons it’s just called
+// "imports" within the examples of this repo.
+// For copying: eslint-disable-next-line simple-import-sort/imports
+// eslint-disable-next-line imports
 import d from "d";
 import c from "c";
 
-// Note that putting a `eslint-disable-next-line simple-import-sort/sort`
+// Note that putting a `eslint-disable-next-line simple-import-sort/imports`
 // comment in the middle of a chunk of imports WON’T WORK. It HAS to be at the
 // very start!
 

examples/readme-exports-grouping-less-comments.prettier.js

@@ -0,0 +1,6 @@
+export * from "./";
+/* This one does not. */ export * from "a"; // Neither does this one.
+/* Nor this
+one */ export * from "b";
+export * from "x";
+export * from "y";

examples/readme-exports-grouping.prettier.js

@@ -0,0 +1,9 @@
+export * from "x";
+export * from "y";
+
+// This comment starts a new group.
+/* This one does not. */ export * from "a"; // Neither does this one.
+/* Nor this
+one */ export * from "b";
+/* But this one does. */
+export * from "./";

examples/readme-order-items.prettier.js

@@ -0,0 +1,28 @@
+import {
+  // First, type imports. (`export { type x, typeof y }` is a syntax error).
+  type x,
+  typeof y,
+  // Numbers are sorted by their numeric value:
+  img1,
+  img2,
+  img10,
+  // Then everything else, alphabetically:
+  k,
+  L, // Case insensitive.
+  m as anotherName, // Sorted by the “external interface” name “m”, not “anotherName”.
+  m as tie, // But do use the file-local name in case of a tie.
+  n,
+} from "./x";
+
+export {
+  k,
+  L, // Case insensitive.
+  anotherName as m, // Sorted by the “external interface” name “m”, not “anotherName”.
+  // tie as m, // For exports there can’t be ties – all exports must be unique.
+  n,
+};
+export type { A, B, A as C };
+
+var k_, L_, anotherName_, n_;
+type A = 1;
+type B = 1;

examples/readme-order.prettier.js

@@ -12,30 +12,44 @@ import b from "https://example.com/script.js";
 // Absolute imports and other imports.
 import c from "/";
 import d from "/home/user/foo";
-import Error from "@/components/error.vue"
+import Error from "@/components/error.vue";
 
 // Relative imports.
 import e from "../..";
-import f from "../../Utils"; // Case insensitive.
 import type { B } from "../types";
 import typeof C from "../types";
+import f from "../Utils"; // Case insensitive.
 import g from ".";
 import h from "./constants";
 import i from "./styles";
 
-// Regardless of group, imported items are sorted like this:
-import {
-  // First, type imports.
-  type x,
-  typeof y,
-  // Then everything else, alphabetically:
-  k,
-  L, // Case insensitive.
-  m as anotherName, // Sorted by the original name “m”, not “anotherName”.
-  m as tie, // But do use the `as` name in case of a tie.
-  n,
-  // Numbers are sorted by their numeric value:
-  img1,
-  img2,
-  img10,
-} from "./x";
+// Different types of exports:
+export { a } from "../..";
+export { b } from "/";
+export { Error } from "@/components/error.vue";
+export * from "an-npm-package";
+export { readFile } from "fs";
+export * as ns from "https://example.com/script.js";
+
+// This comment groups some more exports:
+export { e } from "../..";
+export { f } from "../Utils";
+export { g } from ".";
+export { h } from "./constants";
+export { i } from "./styles";
+
+// Other exports – the plugin does not touch these, other than sorting named
+// exports inside braces.
+export var one = 1;
+export let two = 2;
+export const three = 3;
+export function func() {}
+export class Class {}
+export type Type = string;
+export { named, other as renamed };
+export type { T, U as V };
+export default whatever;
+
+var named, other;
+type T = 1;
+type U = 1;

src/exports.js

@@ -0,0 +1,91 @@
+"use strict";
+
+const shared = require("./shared");
+
+module.exports = {
+  meta: {
+    type: "layout",
+    fixable: "code",
+    schema: [],
+    docs: {
+      url:
+        "https://github.com/lydell/eslint-plugin-simple-import-sort#sort-order",
+    },
+    messages: {
+      sort: "Run autofix to sort these exports!",
+    },
+  },
+  create: (context) => ({
+    Program: (programNode) => {
+      const sourceCode = context.getSourceCode();
+      for (const chunk of shared.extractChunks(programNode, (node, lastNode) =>
+        isPartOfChunk(node, lastNode, sourceCode)
+      )) {
+        maybeReportChunkSorting(chunk, context);
+      }
+    },
+    ExportNamedDeclaration: (node) => {
+      if (node.source == null && node.declaration == null) {
+        maybeReportExportSpecifierSorting(node, context);
+      }
+    },
+  }),
+};
+
+function maybeReportChunkSorting(chunk, context) {
+  const sourceCode = context.getSourceCode();
+  const items = shared.getImportExportItems(
+    chunk,
+    sourceCode,
+    () => false, // isSideEffectImport
+    getSpecifiers
+  );
+  const sortedItems = [[shared.sortImportExportItems(items)]];
+  const sorted = shared.printSortedItems(sortedItems, items, sourceCode);
+  const { start } = items[0];
+  const { end } = items[items.length - 1];
+  shared.maybeReportSorting(context, sorted, start, end);
+}
+
+function maybeReportExportSpecifierSorting(node, context) {
+  const sorted = shared.printWithSortedSpecifiers(
+    node,
+    context.getSourceCode(),
+    getSpecifiers
+  );
+  const [start, end] = node.range;
+  shared.maybeReportSorting(context, sorted, start, end);
+}
+
+// `export * from "a"` does not have `.specifiers`.
+function getSpecifiers(exportNode) {
+  return exportNode.specifiers || [];
+}
+
+function isPartOfChunk(node, lastNode, sourceCode) {
+  if (!isExportFrom(node)) {
+    return "NotPartOfChunk";
+  }
+
+  const hasGroupingComment = sourceCode
+    .getCommentsBefore(node)
+    .some(
+      (comment) =>
+        (lastNode == null || comment.loc.start.line > lastNode.loc.end.line) &&
+        comment.loc.end.line < node.loc.start.line
+    );
+
+  return hasGroupingComment ? "PartOfNewChunk" : "PartOfChunk";
+}
+
+// Full export-from statement.
+// export {a, b} from "A"
+// export * from "A"
+// export * as A from "A"
+function isExportFrom(node) {
+  return (
+    (node.type === "ExportNamedDeclaration" ||
+      node.type === "ExportAllDeclaration") &&
+    node.source != null
+  );
+}