fix(rules): no-missing-exports supports arrays

It seems like if a subpath export is an array, Node uses only the first item of that array and ignores everything else.
boneskull · Aug 24, 2023 · 6dc69c2 · 6dc69c2
1 parent ef4ef53
commit 6dc69c2
Show file tree

Hide file tree

Showing 9 changed files with 171 additions and 30 deletions.
diff --git a/src/rules/builtin/no-missing-exports.ts b/src/rules/builtin/no-missing-exports.ts
@@ -14,6 +14,14 @@ const CONDITIONAL_EXPORT_REQUIRE = 'require';
 const CONDITIONAL_EXPORT_IMPORT = 'import';
 const CONDITIONAL_EXPORT_TYPES = 'types';
 
+type ExportsField =
+  | string
+  | string[]
+  | Record<
+      string,
+      string | null | string[] | Record<string, string | null | string[]>
+    >;
+
 function isESMPkg(pkgJson: PackageJson) {
   return 'type' in pkgJson && pkgJson.type === 'module';
 }
@@ -138,7 +146,10 @@ const noMissingExports = createRule({
      * `RuleFailure` if the `default` key is _not_ the last key in the object
      * @param exports Conditional or subpath exports
      */
-    const checkOrder = (exports: Record<string, string | null>) => {
+    const checkOrder = (exports: ExportsField) => {
+      if (!exports || typeof exports === 'string' || Array.isArray(exports)) {
+        return;
+      }
       if (opts?.order && CONDITIONAL_EXPORT_DEFAULT in exports) {
         const keys = Object.keys(exports);
         if (keys[keys.length - 1] !== CONDITIONAL_EXPORT_DEFAULT) {
@@ -151,49 +162,67 @@ const noMissingExports = createRule({
       }
     };
 
-    const exports = pkgJson[EXPORTS_FIELD] as
-      | string
-      | null
-      | Record<string, string | null>;
+    const exports = pkgJson[EXPORTS_FIELD] as ExportsField;
 
     if (exports === null) {
       return [fail(`"${EXPORTS_FIELD}" field canot be null`)];
     }
 
     // yeah yeah
     let result:
-      | (CheckFailure | undefined | (CheckFailure | undefined)[])[]
-      | CheckFailure
+      | (
+          | CheckFailure
+          | undefined
+          | (CheckFailure | undefined)[]
+          | (CheckFailure | undefined | (CheckFailure | undefined)[])[]
+        )[]
       | undefined;
 
     if (typeof exports === 'string') {
-      result = await checkFile(exports);
+      result = [await checkFile(exports)];
+    } else if (Array.isArray(exports)) {
+      result = await Promise.all(
+        exports.map(async (relativePath) => checkFile(relativePath)),
+      );
     } else {
       result =
         checkOrder(exports) ??
         (await Promise.all(
-          Object.entries(exports).map(([name, relativePath]) => {
-            // most certainly an object
-            if (relativePath && typeof relativePath === 'object') {
-              return (
-                checkOrder(relativePath) ??
-                Promise.all(
-                  Object.entries(relativePath).map(
-                    ([deepName, relativePath]) => {
-                      // don't think this can be an object, but might be wrong!
-                      return checkFile(
-                        relativePath as string | null,
-                        deepName,
-                        `${name} » ${deepName}`,
-                      );
-                    },
-                  ),
-                )
+          Object.entries(exports).map(async ([topKey, topValue]) => {
+            if (topValue === null) {
+              return undefined;
+            }
+            if (typeof topValue === 'string') {
+              return checkFile(topValue, topKey);
+            }
+            if (Array.isArray(topValue)) {
+              if (topKey.startsWith('.')) {
+                return fail(
+                  `Subpath export "${topKey}" should be a string instead of an array`,
+                );
+              }
+              return Promise.all(
+                topValue.map(async (file) => checkFile(file, topKey)),
               );
             }
-
-            // string or null
-            return checkFile(relativePath, name);
+            return (
+              checkOrder(topValue) ??
+              Promise.all(
+                Object.entries(topValue).map(async ([key, value]) => {
+                  if (typeof value === 'string') {
+                    return checkFile(value, key, `${topKey} » ${key}`);
+                  }
+                  if (Array.isArray(value)) {
+                    return Promise.all(
+                      value.map(async (file) =>
+                        checkFile(file, key, `${topKey} » ${key}`),
+                      ),
+                    );
+                  }
+                  return undefined;
+                }),
+              )
+            );
           }),
         ));
     }

diff --git a/test/e2e/rules/fixture/no-missing-exports-array/index.js b/test/e2e/rules/fixture/no-missing-exports-array/index.js
@@ -0,0 +1 @@
+export default {};
diff --git a/test/e2e/rules/fixture/no-missing-exports-array/package.json b/test/e2e/rules/fixture/no-missing-exports-array/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "no-missing-exports-array",
+  "version": "1.0.0",
+  "exports": [
+    "./index.js",
+    "./index-missing.js"
+  ],
+  "type": "module"
+}
diff --git a/test/e2e/rules/fixture/no-missing-exports-conditional-array/index.js b/test/e2e/rules/fixture/no-missing-exports-conditional-array/index.js
@@ -0,0 +1 @@
+export default {};
diff --git a/test/e2e/rules/fixture/no-missing-exports-conditional-array/package.json b/test/e2e/rules/fixture/no-missing-exports-conditional-array/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "no-missing-exports-conditional-array",
+  "version": "1.0.0",
+  "exports": {
+    "default": [
+      "./index.js",
+      "./index-missing.js"
+    ]
+  },
+  "type": "module"
+}
diff --git a/test/e2e/rules/fixture/no-missing-exports-subpath-array/another-index.cjs b/test/e2e/rules/fixture/no-missing-exports-subpath-array/another-index.cjs
@@ -0,0 +1 @@
+module.exports = 2;
diff --git a/test/e2e/rules/fixture/no-missing-exports-subpath-array/index.js b/test/e2e/rules/fixture/no-missing-exports-subpath-array/index.js
@@ -0,0 +1 @@
+export default {};
diff --git a/test/e2e/rules/fixture/no-missing-exports-subpath-array/package.json b/test/e2e/rules/fixture/no-missing-exports-subpath-array/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "no-missing-exports-subpath",
+  "version": "1.0.0",
+  "exports": {
+    ".": [
+      "./index.js",
+      "./another-index.cjs"
+    ]
+  },
+  "type": "module"
+}
diff --git a/test/e2e/rules/no-missing-exports.spec.ts b/test/e2e/rules/no-missing-exports.spec.ts
@@ -86,7 +86,7 @@ describe('midnight-smoker', function () {
         });
       });
 
-      describe('when the package contains subpath "exports"', function () {
+      describe('when the package contains subpath "exports" field', function () {
         describe('when a file is missing', function () {
           beforeEach(function () {
             ({ruleConfig, pkg} = setupRuleTest('no-missing-exports-subpath'));
@@ -109,6 +109,32 @@ describe('midnight-smoker', function () {
               },
             );
           });
+
+          describe('when the value is an array', function () {
+            beforeEach(function () {
+              ({ruleConfig, pkg} = setupRuleTest(
+                'no-missing-exports-subpath-array',
+              ));
+            });
+
+            it('should return a RuleFailure', async function () {
+              await expect(
+                applyRules(ruleConfig, pkg, ruleCont),
+                'to be fulfilled with value satisfying',
+                {
+                  passed: expect.it('to be empty'),
+                  failed: [
+                    {
+                      rule: noMissingExports.toJSON(),
+                      message:
+                        'Subpath export "." should be a string instead of an array',
+                      failed: true,
+                    },
+                  ],
+                },
+              );
+            });
+          });
         });
 
         describe('when no files are missing', function () {
@@ -195,7 +221,7 @@ describe('midnight-smoker', function () {
         });
       });
 
-      describe('when the package contains conditional "exports"', function () {
+      describe('when the package contains conditional "exports" field', function () {
         describe('when a file is missing', function () {
           beforeEach(function () {
             ({ruleConfig, pkg} = setupRuleTest(
@@ -222,6 +248,32 @@ describe('midnight-smoker', function () {
           });
         });
 
+        describe('when the value is an array', function () {
+          beforeEach(function () {
+            ({ruleConfig, pkg} = setupRuleTest(
+              'no-missing-exports-conditional-array',
+            ));
+          });
+
+          it('should return a RuleFailure', async function () {
+            await expect(
+              applyRules(ruleConfig, pkg, ruleCont),
+              'to be fulfilled with value satisfying',
+              {
+                passed: expect.it('to be empty'),
+                failed: [
+                  {
+                    rule: noMissingExports.toJSON(),
+                    message:
+                      'Export "default" unreadable at path: ./index-missing.js',
+                    failed: true,
+                  },
+                ],
+              },
+            );
+          });
+        });
+
         describe('when no files are missing', function () {
           beforeEach(function () {
             ({ruleConfig, pkg} = setupRuleTest(
@@ -363,6 +415,31 @@ describe('midnight-smoker', function () {
           });
         });
       });
+
+      describe('when the package contains an array "exports" field', function () {
+        describe('when a file is missing', function () {
+          beforeEach(function () {
+            ({ruleConfig, pkg} = setupRuleTest('no-missing-exports-array'));
+          });
+
+          it('should return a RuleFailure', async function () {
+            await expect(
+              applyRules(ruleConfig, pkg, ruleCont),
+              'to be fulfilled with value satisfying',
+              {
+                passed: expect.it('to be empty'),
+                failed: [
+                  {
+                    rule: noMissingExports.toJSON(),
+                    message: 'Export unreadable at path: ./index-missing.js',
+                    failed: true,
+                  },
+                ],
+              },
+            );
+          });
+        });
+      });
     });
   });
 });