Refactor export declaration print (#14546)

src/language-js/print/decorators.js

@@ -20,6 +20,12 @@ function printClassMemberDecorators(path, options, print) {
 }
 
 function printDecoratorsBeforeExport(path, options, print) {
+  // Only print decorators here if they were written before the export,
+  // otherwise they are printed by the node.declaration
+  if (!hasDecoratorsBeforeExport(path.node)) {
+    return "";
+  }
+
   // Export declarations are responsible for printing any decorators
   // that logically apply to node.declaration.
   return [

src/language-js/print/flow.js

@@ -27,7 +27,7 @@ import {
 } from "./type-annotation.js";
 import { printInterface } from "./interface.js";
 import { printTypeParameter, printTypeParameters } from "./type-parameters.js";
-import { printExportDeclaration, printExportAllDeclaration } from "./module.js";
+import { printExportDeclaration } from "./module.js";
 import { printArray } from "./array.js";
 import { printObject } from "./object.js";
 import { printPropertyKey } from "./property.js";
@@ -77,9 +77,8 @@ function printFlow(path, options, print) {
         semi,
       ];
     case "DeclareExportDeclaration":
-      return printExportDeclaration(path, options, print);
     case "DeclareExportAllDeclaration":
-      return printExportAllDeclaration(path, options, print);
+      return printExportDeclaration(path, options, print);
     case "DeclareOpaqueType":
     case "OpaqueType":
       return printOpaqueType(path, options, print);

src/language-js/print/module.js

@@ -18,12 +18,10 @@ import {
   needsHardlineAfterDanglingComment,
   isStringLiteral,
   rawText,
+  createTypeCheckFunction,
 } from "../utils/index.js";
 import { locStart, hasSameLoc } from "../loc.js";
-import {
-  hasDecoratorsBeforeExport,
-  printDecoratorsBeforeExport,
-} from "./decorators.js";
+import { printDecoratorsBeforeExport } from "./decorators.js";
 import { printDeclareToken } from "./misc.js";
 
 /**
@@ -32,56 +30,41 @@ import { printDeclareToken } from "./misc.js";
 
 function printImportDeclaration(path, options, print) {
   const { node } = path;
-  const semi = options.semi ? ";" : "";
   /** @type{Doc[]} */
-  const parts = [];
-
-  const { importKind } = node;
-
-  parts.push("import");
-
-  if (node.module) {
-    parts.push(" module");
-  }
-
-  if (importKind && importKind !== "value") {
-    parts.push(" ", importKind);
-  }
-
-  parts.push(
+  return [
+    "import",
+    node.module ? " module" : "",
+    printImportKind(node),
     printModuleSpecifiers(path, options, print),
     printModuleSource(path, options, print),
     printImportAssertions(path, options, print),
-    semi
-  );
-
-  return parts;
+    options.semi ? ";" : "",
+  ];
 }
 
+const isDefaultExport = (node) =>
+  node.type === "ExportDefaultDeclaration" ||
+  (node.type === "DeclareExportDeclaration" && node.default);
+
 /*
 - `ExportDefaultDeclaration`
 - `ExportNamedDeclaration`
 - `DeclareExportDeclaration`(flow)
+- `ExportAllDeclaration`
+- `DeclareExportAllDeclaration`(flow)
 */
 function printExportDeclaration(path, options, print) {
   const { node } = path;
+
   /** @type{Doc[]} */
-  const parts = [];
+  const parts = [
+    printDecoratorsBeforeExport(path, options, print),
+    printDeclareToken(path),
+    "export",
+    isDefaultExport(node) ? " default" : "",
+  ];
 
-  // Only print decorators here if they were written before the export,
-  // otherwise they are printed by the node.declaration
-  if (hasDecoratorsBeforeExport(node)) {
-    parts.push(printDecoratorsBeforeExport(path, options, print));
-  }
-
-  const { type, exportKind, declaration } = node;
-
-  parts.push(printDeclareToken(path), "export");
-
-  const isDefaultExport = node.default || type === "ExportDefaultDeclaration";
-  if (isDefaultExport) {
-    parts.push(" default");
-  }
+  const { declaration, exported } = node;
 
   if (hasComment(node, CommentCheckFlags.Dangling)) {
     parts.push(" ", printDanglingComments(path, options));
@@ -94,77 +77,64 @@ function printExportDeclaration(path, options, print) {
   if (declaration) {
     parts.push(" ", print("declaration"));
   } else {
+    parts.push(printExportKind(node));
+
+    if (
+      node.type === "ExportAllDeclaration" ||
+      node.type === "DeclareExportAllDeclaration"
+    ) {
+      parts.push(" *");
+      if (exported) {
+        parts.push(" as ", print("exported"));
+      }
+    } else {
+      parts.push(printModuleSpecifiers(path, options, print));
+    }
+
     parts.push(
-      exportKind === "type" ? " type" : "",
-      printModuleSpecifiers(path, options, print),
       printModuleSource(path, options, print),
       printImportAssertions(path, options, print)
     );
   }
 
-  if (shouldExportDeclarationPrintSemi(node, options)) {
-    parts.push(";");
-  }
+  parts.push(printSemicolonAfterExportDeclaration(node, options));
 
   return parts;
 }
 
-/*
-- `ExportAllDeclaration`
-- `DeclareExportAllDeclaration`(flow)
-*/
-function printExportAllDeclaration(path, options, print) {
-  const { node } = path;
-  const semi = options.semi ? ";" : "";
-  /** @type{Doc[]} */
-  const parts = [printDeclareToken(path), "export"];
-
-  const { exportKind, exported } = node;
-
-  if (exportKind === "type") {
-    parts.push(" type");
-  }
-
-  parts.push(" *");
-
-  if (exported) {
-    parts.push(" as ", print("exported"));
-  }
-
-  parts.push(
-    printModuleSource(path, options, print),
-    printImportAssertions(path, options, print),
-    semi
-  );
-
-  return parts;
-}
-
-function shouldExportDeclarationPrintSemi(node, options) {
-  if (!options.semi) {
-    return false;
-  }
-
-  const { type, declaration } = node;
-  const isDefaultExport = node.default || type === "ExportDefaultDeclaration";
-  if (!declaration) {
-    return true;
-  }
-
-  const { type: declarationType } = declaration;
+const shouldOmitSemicolon = createTypeCheckFunction([
+  "ClassDeclaration",
+  "FunctionDeclaration",
+  "TSInterfaceDeclaration",
+  "DeclareClass",
+  "DeclareFunction",
+  "TSDeclareFunction",
+  "EnumDeclaration",
+]);
+function printSemicolonAfterExportDeclaration(node, options) {
   if (
-    isDefaultExport &&
-    declarationType !== "ClassDeclaration" &&
-    declarationType !== "FunctionDeclaration" &&
-    declarationType !== "TSInterfaceDeclaration" &&
-    declarationType !== "DeclareClass" &&
-    declarationType !== "DeclareFunction" &&
-    declarationType !== "TSDeclareFunction" &&
-    declarationType !== "EnumDeclaration"
+    options.semi &&
+    (!node.declaration ||
+      (isDefaultExport(node) && !shouldOmitSemicolon(node.declaration)))
   ) {
-    return true;
+    return ";";
   }
-  return false;
+
+  return "";
+}
+
+function printImportOrExportKind(kind, spaceBeforeKind = true) {
+  return kind && kind !== "value"
+    ? `${spaceBeforeKind ? " " : ""}${kind}${spaceBeforeKind ? "" : " "}`
+    : "";
+}
+
+function printImportKind(node, spaceBeforeKind) {
+  return printImportOrExportKind(node.importKind, spaceBeforeKind);
+}
+
+function printExportKind(node) {
+  return printImportOrExportKind(node.exportKind);
 }
 
 function printModuleSource(path, options, print) {
@@ -278,36 +248,26 @@ function shouldNotPrintSpecifiers(node, options) {
 
 function printImportAssertions(path, options, print) {
   const { node } = path;
-  if (isNonEmptyArray(node.assertions)) {
-    return [
-      " assert {",
-      options.bracketSpacing ? " " : "",
-      join(", ", path.map(print, "assertions")),
-      options.bracketSpacing ? " " : "",
-      "}",
-    ];
+  if (!isNonEmptyArray(node.assertions)) {
+    return "";
   }
-  return "";
+
+  return [
+    " assert {",
+    options.bracketSpacing ? " " : "",
+    join(", ", path.map(print, "assertions")),
+    options.bracketSpacing ? " " : "",
+    "}",
+  ];
 }
 
 function printModuleSpecifier(path, options, print) {
   const { node } = path;
-
   const { type } = node;
 
-  /** @type {Doc[]} */
-  const parts = [];
-
-  /** @type {"type" | "typeof" | "value"} */
-  const kind = type === "ImportSpecifier" ? node.importKind : node.exportKind;
-
-  if (kind && kind !== "value") {
-    parts.push(kind, " ");
-  }
-
-  const isImport = type.startsWith("Import");
-  const leftSideProperty = isImport ? "imported" : "local";
-  const rightSideProperty = isImport ? "local" : "exported";
+  const isImportSpecifier = type.startsWith("Import");
+  const leftSideProperty = isImportSpecifier ? "imported" : "local";
+  const rightSideProperty = isImportSpecifier ? "local" : "exported";
   const leftSideNode = node[leftSideProperty];
   const rightSideNode = node[rightSideProperty];
   let left = "";
@@ -325,8 +285,15 @@ function printModuleSpecifier(path, options, print) {
     right = print(rightSideProperty);
   }
 
-  parts.push(left, left && right ? " as " : "", right);
-  return parts;
+  return [
+    printImportOrExportKind(
+      type === "ImportSpecifier" ? node.importKind : node.exportKind,
+      /* spaceBeforeKind */ false
+    ),
+    left,
+    left && right ? " as " : "",
+    right,
+  ];
 }
 
 function isShorthandSpecifier(specifier) {
@@ -369,6 +336,6 @@ function isShorthandSpecifier(specifier) {
 export {
   printImportDeclaration,
   printExportDeclaration,
-  printExportAllDeclaration,
   printModuleSpecifier,
+  printImportKind,
 };

src/language-js/print/typescript.js

@@ -56,6 +56,7 @@ import {
   printTypeQuery,
 } from "./type-annotation.js";
 import { printEnumDeclaration, printEnumMember } from "./enum.js";
+import { printImportKind } from "./module.js";
 
 function printTypescript(path, options, print) {
   const { node } = path;
@@ -302,13 +303,7 @@ function printTypescript(path, options, print) {
       return group(parts);
     }
     case "TSNamespaceExportDeclaration":
-      parts.push("export as namespace ", print("id"));
-
-      if (options.semi) {
-        parts.push(";");
-      }
-
-      return group(parts);
+      return ["export as namespace ", print("id"), options.semi ? ";" : ""];
     case "TSEnumDeclaration":
       return printEnumDeclaration(path, print, options);
 
@@ -316,23 +311,15 @@ function printTypescript(path, options, print) {
       return printEnumMember(path, print);
 
     case "TSImportEqualsDeclaration":
-      if (node.isExport) {
-        parts.push("export ");
-      }
-
-      parts.push("import ");
-
-      if (node.importKind && node.importKind !== "value") {
-        parts.push(node.importKind, " ");
-      }
-
-      parts.push(print("id"), " = ", print("moduleReference"));
-
-      if (options.semi) {
-        parts.push(";");
-      }
-
-      return group(parts);
+      return [
+        node.isExport ? "export " : "",
+        "import ",
+        printImportKind(node, /* spaceBeforeKind */ false),
+        print("id"),
+        " = ",
+        print("moduleReference"),
+        options.semi ? ";" : "",
+      ];
     case "TSExternalModuleReference":
       return ["require(", print("expression"), ")"];
     case "TSModuleDeclaration": {

src/language-js/printer-estree.js

@@ -56,7 +56,6 @@ import {
 import {
   printImportDeclaration,
   printExportDeclaration,
-  printExportAllDeclaration,
   printModuleSpecifier,
 } from "./print/module.js";
 import { printTernary } from "./print/ternary.js";
@@ -339,9 +338,8 @@ function printPathNoParens(path, options, print, args) {
 
     case "ExportDefaultDeclaration":
     case "ExportNamedDeclaration":
-      return printExportDeclaration(path, options, print);
     case "ExportAllDeclaration":
-      return printExportAllDeclaration(path, options, print);
+      return printExportDeclaration(path, options, print);
     case "ImportDeclaration":
       return printImportDeclaration(path, options, print);
     case "ImportSpecifier":