style: no-use-before-define is now more harsh.

Author: Rebecca Stevens

.eslintrc

@@ -76,10 +76,10 @@
     "@typescript-eslint/no-use-before-define": [
       "error",
       {
-        "functions": false,
-        "classes": false,
+        "functions": true,
+        "classes": true,
         "variables": true,
-        "typedefs": false
+        "typedefs": true
       }
     ],
 

src/common/ignore-options.ts

@@ -125,45 +125,18 @@ export const ignoreNewArrayOptionSchema: JSONSchema4 = {
   additionalProperties: false
 };
 
-/**
- * Should the given node be ignored?
- */
-export function shouldIgnore(
-  node: TSESTree.Node,
-  context: RuleContext<string, BaseOptions>,
-  options: Partial<IgnoreOptions>
-): boolean {
-  return (
-    // Ignore if in a function and ignoreLocal is set.
-    (Boolean(options.ignoreLocal) && inFunction(node)) ||
-    // Ignore if in a class and ignoreClass is set.
-    (Boolean(options.ignoreClass) && inClass(node)) ||
-    // Ignore if in an interface and ignoreInterface is set.
-    (Boolean(options.ignoreInterface) && inInterface(node)) ||
-    ((texts: ReadonlyArray<string>): boolean =>
-      texts.length > 0
-        ? // Ignore if ignorePattern is set and a pattern matches.
-          (options.ignorePattern !== undefined &&
-            texts.every(text =>
-              isIgnoredPattern(text, options.ignorePattern!)
-            )) ||
-          // Ignore if ignoreAccessorPattern is set and an accessor pattern matches.
-          (options.ignoreAccessorPattern !== undefined &&
-            texts.every(text =>
-              isIgnoredAccessorPattern(text, options.ignoreAccessorPattern!)
-            ))
-        : false)(getNodeTexts(node, context))
-  );
-}
-
-function getNodeTexts(
+function _getNodeText(
   node: TSESTree.Node,
   context: RuleContext<string, BaseOptions>
-): ReadonlyArray<string> {
-  return (isVariableDeclaration(node)
-    ? node.declarations.flatMap(declarator => getNodeText(declarator, context))
-    : [getNodeText(node, context)]
-  ).filter(name => name !== undefined) as ReadonlyArray<string>;
+): string {
+  return isIdentifier(node)
+    ? node.name
+    : isMemberExpression(node)
+    ? `${_getNodeText(node.object, context)}.${_getNodeText(
+        node.property,
+        context
+      )}`
+    : context.getSourceCode().getText(node);
 }
 
 function getNodeText(
@@ -183,18 +156,14 @@ function getNodeText(
     : _getNodeText(node, context);
 }
 
-function _getNodeText(
+function getNodeTexts(
   node: TSESTree.Node,
   context: RuleContext<string, BaseOptions>
-): string {
-  return isIdentifier(node)
-    ? node.name
-    : isMemberExpression(node)
-    ? `${_getNodeText(node.object, context)}.${_getNodeText(
-        node.property,
-        context
-      )}`
-    : context.getSourceCode().getText(node);
+): ReadonlyArray<string> {
+  return (isVariableDeclaration(node)
+    ? node.declarations.flatMap(declarator => getNodeText(declarator, context))
+    : [getNodeText(node, context)]
+  ).filter(name => name !== undefined) as ReadonlyArray<string>;
 }
 
 function isIgnoredPattern(
@@ -209,20 +178,6 @@ function isIgnoredPattern(
   return patterns.some(pattern => new RegExp(pattern).test(text));
 }
 
-function isIgnoredAccessorPattern(
-  text: string,
-  ignorePattern: ReadonlyArray<string> | string
-): boolean {
-  const patterns: ReadonlyArray<string> = Array.isArray(ignorePattern)
-    ? ignorePattern
-    : [ignorePattern];
-
-  // One or more patterns match?
-  return patterns.some(pattern =>
-    findMatch(pattern.split("."), text.split("."))
-  );
-}
-
 function findMatch(
   [pattern, ...remainingPatternParts]: ReadonlyArray<string>,
   textParts: ReadonlyArray<string>,
@@ -248,3 +203,48 @@ function findMatch(
         textParts[0]
       ) && findMatch(remainingPatternParts, textParts.slice(1), allowExtra);
 }
+
+function isIgnoredAccessorPattern(
+  text: string,
+  ignorePattern: ReadonlyArray<string> | string
+): boolean {
+  const patterns: ReadonlyArray<string> = Array.isArray(ignorePattern)
+    ? ignorePattern
+    : [ignorePattern];
+
+  // One or more patterns match?
+  return patterns.some(pattern =>
+    findMatch(pattern.split("."), text.split("."))
+  );
+}
+
+/**
+ * Should the given node be ignored?
+ */
+export function shouldIgnore(
+  node: TSESTree.Node,
+  context: RuleContext<string, BaseOptions>,
+  options: Partial<IgnoreOptions>
+): boolean {
+  return (
+    // Ignore if in a function and ignoreLocal is set.
+    (Boolean(options.ignoreLocal) && inFunction(node)) ||
+    // Ignore if in a class and ignoreClass is set.
+    (Boolean(options.ignoreClass) && inClass(node)) ||
+    // Ignore if in an interface and ignoreInterface is set.
+    (Boolean(options.ignoreInterface) && inInterface(node)) ||
+    ((texts: ReadonlyArray<string>): boolean =>
+      texts.length > 0
+        ? // Ignore if ignorePattern is set and a pattern matches.
+          (options.ignorePattern !== undefined &&
+            texts.every(text =>
+              isIgnoredPattern(text, options.ignorePattern!)
+            )) ||
+          // Ignore if ignoreAccessorPattern is set and an accessor pattern matches.
+          (options.ignoreAccessorPattern !== undefined &&
+            texts.every(text =>
+              isIgnoredAccessorPattern(text, options.ignoreAccessorPattern!)
+            ))
+        : false)(getNodeTexts(node, context))
+  );
+}

src/rules/functional-parameters.ts

@@ -83,26 +83,6 @@ const meta: RuleMetaData<keyof typeof errorMessages> = {
   schema
 };
 
-/**
- * Check if the given function node has a reset parameter this rule.
- */
-function checkFunction(
-  node:
-    | TSESTree.FunctionDeclaration
-    | TSESTree.FunctionExpression
-    | TSESTree.ArrowFunctionExpression,
-  context: RuleContext<keyof typeof errorMessages, Options>,
-  options: Options
-): RuleResult<keyof typeof errorMessages, Options> {
-  return {
-    context,
-    descriptors: [
-      ...getRestParamViolations(options.allowRestParameter, node),
-      ...getParamCountViolations(options.enforceParameterCount, node)
-    ]
-  };
-}
-
 function getRestParamViolations(
   allowRestParameter: boolean,
   node:
@@ -146,6 +126,26 @@ function getParamCountViolations(
     : [];
 }
 
+/**
+ * Check if the given function node has a reset parameter this rule.
+ */
+function checkFunction(
+  node:
+    | TSESTree.FunctionDeclaration
+    | TSESTree.FunctionExpression
+    | TSESTree.ArrowFunctionExpression,
+  context: RuleContext<keyof typeof errorMessages, Options>,
+  options: Options
+): RuleResult<keyof typeof errorMessages, Options> {
+  return {
+    context,
+    descriptors: [
+      ...getRestParamViolations(options.allowRestParameter, node),
+      ...getParamCountViolations(options.enforceParameterCount, node)
+    ]
+  };
+}
+
 /**
  * Check if the given identifier is for the "arguments" keyword.
  */

src/rules/immutable-data.ts

@@ -195,6 +195,47 @@ function checkUpdateExpression(
   };
 }
 
+/**
+ * Check if the given the given MemberExpression is part of a chain and
+ * immediately follows a method/function call that returns a new array.
+ *
+ * If this is the case, then the given MemberExpression is allowed to be
+ * a mutator method call.
+ */
+function isInChainCallAndFollowsNew(
+  node: TSESTree.MemberExpression,
+  context: RuleContext<keyof typeof errorMessages, Options>,
+  assumeArrayTypes: boolean
+): boolean {
+  return (
+    // Check for: [0, 1, 2]
+    isArrayExpression(node.object) ||
+    // Check for: new Array()
+    ((isNewExpression(node.object) &&
+      isArrayConstructorType(
+        getTypeOfNode(node.object.callee, context),
+        assumeArrayTypes,
+        node.object.callee
+      )) ||
+      (isCallExpression(node.object) &&
+        isMemberExpression(node.object.callee) &&
+        isIdentifier(node.object.callee.property) &&
+        // Check for: Array.from(iterable)
+        ((arrayConstructorFunctions.some(
+          isExpected(node.object.callee.property.name)
+        ) &&
+          isArrayConstructorType(
+            getTypeOfNode(node.object.callee.object, context),
+            assumeArrayTypes,
+            node.object.callee.object
+          )) ||
+          // Check for: array.slice(0)
+          arrayNewObjectReturningMethods.some(
+            isExpected(node.object.callee.property.name)
+          ))))
+  );
+}
+
 /**
  * Check if the given node violates this rule.
  */
@@ -254,47 +295,6 @@ function checkCallExpression(
   };
 }
 
-/**
- * Check if the given the given MemberExpression is part of a chain and
- * immediately follows a method/function call that returns a new array.
- *
- * If this is the case, then the given MemberExpression is allowed to be
- * a mutator method call.
- */
-function isInChainCallAndFollowsNew(
-  node: TSESTree.MemberExpression,
-  context: RuleContext<keyof typeof errorMessages, Options>,
-  assumeArrayTypes: boolean
-): boolean {
-  return (
-    // Check for: [0, 1, 2]
-    isArrayExpression(node.object) ||
-    // Check for: new Array()
-    ((isNewExpression(node.object) &&
-      isArrayConstructorType(
-        getTypeOfNode(node.object.callee, context),
-        assumeArrayTypes,
-        node.object.callee
-      )) ||
-      (isCallExpression(node.object) &&
-        isMemberExpression(node.object.callee) &&
-        isIdentifier(node.object.callee.property) &&
-        // Check for: Array.from(iterable)
-        ((arrayConstructorFunctions.some(
-          isExpected(node.object.callee.property.name)
-        ) &&
-          isArrayConstructorType(
-            getTypeOfNode(node.object.callee.object, context),
-            assumeArrayTypes,
-            node.object.callee.object
-          )) ||
-          // Check for: array.slice(0)
-          arrayNewObjectReturningMethods.some(
-            isExpected(node.object.callee.property.name)
-          ))))
-  );
-}
-
 // Create the rule.
 export const rule = createRule<keyof typeof errorMessages, Options>(
   name,

src/util/tree.ts

@@ -10,6 +10,20 @@ import {
   isTSInterfaceBody
 } from "./typeguard";
 
+/**
+ * Return the parent that meets the given check criteria.
+ */
+function getParentOfType<T extends TSESTree.Node>(
+  checker: (node: TSESTree.Node) => node is T,
+  node: TSESTree.Node
+): T | null {
+  return checker(node)
+    ? node
+    : node.parent == undefined
+    ? null
+    : getParentOfType(checker, node.parent);
+}
+
 /**
  * Test if the given node is in a function.
  */
@@ -73,17 +87,3 @@ export function isPropertyName(node: TSESTree.Identifier): boolean {
     node.parent.key === node
   );
 }
-
-/**
- * Return the parent that meets the given check criteria.
- */
-function getParentOfType<T extends TSESTree.Node>(
-  checker: (node: TSESTree.Node) => node is T,
-  node: TSESTree.Node
-): T | null {
-  return checker(node)
-    ? node
-    : node.parent == undefined
-    ? null
-    : getParentOfType(checker, node.parent);
-}

tests/util.ts

@@ -24,18 +24,6 @@ export type InvalidTestCase = Omit<
 > &
   OptionsSet;
 
-/**
- * Convert our test cases into ones eslint test runner is expecting.
- */
-export function processValidTestCase(
-  testCases: ReadonlyArray<ValidTestCase>
-): Array<ESLintRuleTester.ValidTestCase> {
-  // Ideally these two functions should be merged into 1 but I haven't been able
-  // to get the typing information right - so for now they are two functions.
-  /* eslint-disable-next-line @typescript-eslint/no-explicit-any */
-  return processInvalidTestCase(testCases as any);
-}
-
 /**
  * Convert our test cases into ones eslint test runner is expecting.
  */
@@ -65,6 +53,18 @@ export function processInvalidTestCase(
   ) as Array<ESLintRuleTester.InvalidTestCase>;
 }
 
+/**
+ * Convert our test cases into ones eslint test runner is expecting.
+ */
+export function processValidTestCase(
+  testCases: ReadonlyArray<ValidTestCase>
+): Array<ESLintRuleTester.ValidTestCase> {
+  // Ideally these two functions should be merged into 1 but I haven't been able
+  // to get the typing information right - so for now they are two functions.
+  /* eslint-disable-next-line @typescript-eslint/no-explicit-any */
+  return processInvalidTestCase(testCases as any);
+}
+
 export function createDummyRule(
   create: (
     /* eslint-disable-next-line @typescript-eslint/no-explicit-any */