Share all identical logic between rules

Author: jj-ivx

lib/rules/no-cross-imports.js

@@ -1,7 +1,7 @@
 'use strict';
 
-const getPackages = require('get-monorepo-packages');
-const { relative, resolve, sep, isAbsolute } = require('path');
+const { isSubPath, packages, getImportValue } = require('../utils');
+const { resolve } = require('path');
 
 module.exports.meta = {
   type: 'problem',
@@ -32,55 +32,26 @@ module.exports.schema = [
   },
 ];
 
-const isSubPath = (parent, path) => {
-  const relativePath = relative(parent, path);
-  return relativePath.split(sep)[0] !== '..' && !isAbsolute(relativePath);
-};
-
-const reportForbiddenPackage = (forbidden, context, node, value) => {
-  forbidden.forEach(({ name, location }) => {
-    if (
-      isSubPath(name, value) ||
-      isSubPath(location, resolve(context.getFilename(), value))
-    ) {
-      context.report({
-        node,
-        message: 'Import from package "{{name}}" is not allowed',
-        data: { name },
-      });
-    }
-  });
-};
-
 module.exports.create = context => {
-  const packages = getPackages(process.cwd()).map(
-    ({ package: { name }, location }) => ({ name, location }),
-  );
-
   const {
     options: [{ allow = [] } = {}],
   } = context;
 
   const allowed = typeof allow === 'string' ? [allow] : allow;
   const forbidden = packages.filter(({ name }) => !allowed.includes(name));
 
-  return {
-    ImportDeclaration: node => {
-      if (node.source.type === 'Literal') {
-        reportForbiddenPackage(forbidden, context, node, node.source.value);
-      }
-    },
-    ExpressionStatement: node => {
+  return getImportValue(context, (value, node) => {
+    forbidden.forEach(({ name, location }) => {
       if (
-        node.expression.type === 'CallExpression' &&
-        node.expression.arguments[0].type === 'Literal' &&
-        (node.expression.callee.type === 'Import' ||
-          (node.expression.callee.type === 'Identifier' &&
-            node.expression.callee.name === 'require'))
+        isSubPath(name, value) ||
+        isSubPath(location, resolve(context.getFilename(), value))
       ) {
-        const { value } = node.expression.arguments[0];
-        reportForbiddenPackage(forbidden, context, node, value);
+        context.report({
+          node,
+          message: 'Import from package "{{name}}" is not allowed',
+          data: { name },
+        });
       }
-    },
-  };
+    });
+  });
 };

lib/rules/no-relative-imports.js

@@ -1,7 +1,7 @@
 'use strict';
 
-const getPackages = require('get-monorepo-packages');
-const { relative, resolve, sep, isAbsolute } = require('path');
+const { isSubPath, packages, getImportValue } = require('../utils');
+const { resolve } = require('path');
 
 module.exports.meta = {
   type: 'problem',
@@ -13,44 +13,16 @@ module.exports.meta = {
 
 module.exports.schema = [];
 
-const isSubPath = (parent, path) => {
-  const relativePath = relative(parent, path);
-  return relativePath.split(sep)[0] !== '..' && !isAbsolute(relativePath);
-};
-
-const isRelativeImport = (packages, context, node, value) => {
-  packages.forEach(location => {
-    if (
-      !isSubPath(location, context.getFilename()) &&
-      isSubPath(location, resolve(context.getFilename(), value))
-    )
-      context.report({
-        node,
-        message: 'Relative imports of other packages are not allowed',
-      });
-  });
-};
-
-module.exports.create = context => {
-  const packages = getPackages(process.cwd()).map(({ location }) => location);
-
-  return {
-    ImportDeclaration: node => {
-      if (node.source.type === 'Literal') {
-        isRelativeImport(packages, context, node, node.source.value);
-      }
-    },
-    ExpressionStatement: node => {
+module.exports.create = context =>
+  getImportValue(context, (value, node) => {
+    packages.forEach(({ location }) => {
       if (
-        node.expression.type === 'CallExpression' &&
-        node.expression.arguments[0].type === 'Literal' &&
-        (node.expression.callee.type === 'Import' ||
-          (node.expression.callee.type === 'Identifier' &&
-            node.expression.callee.name === 'require'))
-      ) {
-        const { value } = node.expression.arguments[0];
-        isRelativeImport(packages, context, node, value);
-      }
-    },
-  };
-};
+        !isSubPath(location, context.getFilename()) &&
+        isSubPath(location, resolve(context.getFilename(), value))
+      )
+        context.report({
+          node,
+          message: 'Relative imports of other packages are not allowed',
+        });
+    });
+  });

lib/utils.js

@@ -0,0 +1,35 @@
+'use strict';
+
+const getPackages = require('get-monorepo-packages');
+const { relative, sep, isAbsolute } = require('path');
+
+const isSubPath = (parent, path) => {
+  const relativePath = relative(parent, path);
+  return relativePath.split(sep)[0] !== '..' && !isAbsolute(relativePath);
+};
+
+const packages = getPackages(process.cwd()).map(
+  ({ package: { name }, location }) => ({ name, location }),
+);
+
+const getImportValue = (context, callback) => ({
+  ImportDeclaration: node => {
+    if (node.source.type === 'Literal') {
+      callback(node.source.value, node);
+    }
+  },
+  ExpressionStatement: node => {
+    if (
+      node.expression.type === 'CallExpression' &&
+      node.expression.arguments[0].type === 'Literal' &&
+      (node.expression.callee.type === 'Import' ||
+        (node.expression.callee.type === 'Identifier' &&
+          node.expression.callee.name === 'require'))
+    ) {
+      const { value } = node.expression.arguments[0];
+      callback(value, node);
+    }
+  },
+});
+
+module.exports = { isSubPath, packages, getImportValue };