Add "check-type-operator" option for whitespace rule (#3083)

Author: santialbo

src/rules/whitespaceRule.ts

@@ -30,6 +30,7 @@ const OPTION_SEPARATOR = "check-separator";
 const OPTION_REST_SPREAD = "check-rest-spread";
 const OPTION_TYPE = "check-type";
 const OPTION_TYPECAST = "check-typecast";
+const OPTION_TYPE_OPERATOR = "check-type-operator";
 const OPTION_PREBLOCK = "check-preblock";
 
 export class Rule extends Lint.Rules.AbstractRule {
@@ -48,16 +49,19 @@ export class Rule extends Lint.Rules.AbstractRule {
  * \`"check-rest-spread"\` checks that there is no whitespace after rest/spread operator (\`...\`).
  * \`"check-type"\` checks for whitespace before a variable type specification.
  * \`"check-typecast"\` checks for whitespace between a typecast and its target.
+ * \`"check-type-operator"\` checks for whitespace between type operators \`|\` and \`&\`.
  * \`"check-preblock"\` checks for whitespace before the opening brace of a block`,
  options: {
  type: "array",
  items: {
  type: "string",
- enum: ["check-branch", "check-decl", "check-operator", "check-module",
- "check-separator", "check-rest-spread", "check-type", "check-typecast", "check-preblock"],
+ enum: [
+ "check-branch", "check-decl", "check-operator", "check-module", "check-separator",
+ "check-rest-spread", "check-type", "check-typecast", "check-type-operator", "check-preblock",
+ ],
  },
  minLength: 0,
- maxLength: 9,
+ maxLength: 10,
  },
  optionExamples: [[true, "check-branch", "check-operator", "check-typecast"]],
  type: "style",
@@ -72,7 +76,10 @@ export class Rule extends Lint.Rules.AbstractRule {
  }
 }
 
-type Options = Record<"branch" | "decl" | "operator" | "module" | "separator" | "restSpread" | "type" | "typecast" | "preblock", boolean>;
+type Options = Record<
+ "branch" | "decl" | "operator" | "module" | "separator" | "restSpread" | "type" | "typecast" | "typeOperator" | "preblock",
+ boolean>;
+
 function parseOptions(ruleArguments: string[]): Options {
  return {
  branch: has(OPTION_BRANCH),
@@ -83,6 +90,7 @@ function parseOptions(ruleArguments: string[]): Options {
  restSpread: has(OPTION_REST_SPREAD),
  type: has(OPTION_TYPE),
  typecast: has(OPTION_TYPECAST),
+ typeOperator: has(OPTION_TYPE_OPERATOR),
  preblock: has(OPTION_PREBLOCK),
  };
 
@@ -194,7 +202,7 @@ function walk(ctx: Lint.WalkContext<Options>) {
  case ts.SyntaxKind.VariableDeclaration:
  const { name, type, initializer } = node as ts.VariableDeclaration;
  if (options.decl && initializer !== undefined) {
- checkForTrailingWhitespace((type !== undefined ? type :  name).getEnd());
+ checkForTrailingWhitespace((type !== undefined ? type : name).getEnd());
  }
  break;
 
@@ -212,6 +220,21 @@ function walk(ctx: Lint.WalkContext<Options>) {
  const position = (node as ts.SpreadAssignment).expression.getFullStart();
  checkForExcessiveWhitespace(position);
  }
+ break;
+
+ case ts.SyntaxKind.UnionType:
+ case ts.SyntaxKind.IntersectionType:
+ if (options.typeOperator) {
+ const { types } = node as ts.UnionOrIntersectionTypeNode;
+ types.forEach((typeNode, index) => {
+ if (index > 0) {
+ checkForTrailingWhitespace(typeNode.getFullStart());
+ }
+ if (index < types.length - 1) {
+ checkForTrailingWhitespace(typeNode.getEnd());
+ }
+ });
+ }
  }
 
  ts.forEachChild(node, cb);
@@ -262,7 +285,7 @@ function walk(ctx: Lint.WalkContext<Options>) {
  (parent as ts.CallExpression).expression.kind === ts.SyntaxKind.ImportKeyword) {
  return; // Don't check ImportCall
  }
-  // falls through
+ // falls through
  case ts.SyntaxKind.ExportKeyword:
  case ts.SyntaxKind.FromKeyword:
  if (options.typecast) {

test/rules/whitespace/all/test.ts.fix

@@ -112,3 +112,9 @@ const foo = [ ...bar ];
 function foo (bar, ...baz) {}
 
 const { foo, ...bar } = baz;
+
+type A = number | string;
+
+type B = number | string | {result: string};
+
+type C = {result: string} & {type: "A" | "B"};

test/rules/whitespace/all/test.ts.lint

@@ -173,3 +173,19 @@ function foo (bar, ... baz) {}
 
 const { foo, ... bar } = baz;
  ~ [invalid whitespace]
+
+type A = number|string;
+ ~ [missing whitespace]
+ ~ [missing whitespace]
+
+type B = number|string|{result: string};
+ ~ [missing whitespace]
+ ~ [missing whitespace]
+ ~ [missing whitespace]
+ ~ [missing whitespace]
+
+type C = {result: string}&{type: "A"|"B"};
+ ~ [missing whitespace]
+ ~ [missing whitespace]
+ ~ [missing whitespace]
+ ~ [missing whitespace]

test/rules/whitespace/all/tslint.json

@@ -9,7 +9,8 @@
  "check-separator",
  "check-rest-spread",
  "check-type",
- "check-typecast"
+ "check-typecast",
+ "check-type-operator"
  ]
  }
 }