feat(rxjs-no-do): Add rule.

README.md

@@ -54,6 +54,7 @@ The package includes the following rules:
 | --- | --- | --- |
 | `rxjs-add` | Enforces the importation of patched observables and operators used in the module. | See below |
 | `rxjs-no-add` | Disallows the importation of patched observables and operators. | None |
+| `rxjs-no-do` | I do without `do` operators. [Do you not?](https://youtu.be/spG-Yj0zEyc) | None |
 | `rxjs-no-patched` | Disallows the calling of patched methods. Operators must be imported and called explicitly - not via the `Observable` prototype. | None |
 | `rxjs-no-subject-unsubscribe` | Disallows the calling of `unsubscribe` directly upon `Subject` instances. For an explanation of why this can be a problem, see [this](https://stackoverflow.com/a/45112125/6680611) Stack Overflow answer. | None |
 | `rxjs-no-unused-add` | Disallows the importation of patched observables or operators that are not used in the module. | None |

fixtures/no-do/fixture.ts

@@ -0,0 +1,5 @@
+import { Observable } from "rxjs";
+import "rxjs/add/observable/of";
+import "rxjs/add/operator/do";
+
+const ob = Observable.of(1).do((value) => console.log(value));

fixtures/no-do/tsconfig.json

@@ -0,0 +1,13 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "lib": ["es2015"],
+    "noEmit": true,
+    "paths": {
+      "rxjs": ["../node_modules/rxjs"]
+    },
+    "skipLibCheck": true,
+    "target": "es5"
+  },
+  "include": ["fixture.ts"]
+}

fixtures/no-do/tslint.json

@@ -0,0 +1,8 @@
+{
+  "defaultSeverity": "error",
+  "jsRules": {},
+  "rules": {
+    "rxjs-no-do": { "severity": "error" }
+  },
+  "rulesDirectory": "../../build/rules"
+}

source/fixtures-spec.ts

@@ -90,6 +90,17 @@ describe("fixtures", function (): void {
             });
         });
 
+        describe("no-do", () => {
+
+            it("should effect 'rxjs-no-do' errors", () => {
+
+                const result = lint("no-do", "tslint.json");
+
+                expect(result).to.have.property("errorCount", 1);
+                expect(result.failures[0]).to.have.property("ruleName", "rxjs-no-do");
+            });
+        });
+
         describe("no-errors", () => {
 
             it("should effect no errors", () => {

source/rules/rxjsNoDoRule.ts

@@ -0,0 +1,41 @@
+/**
+ * @license Copyright © 2017 Nicholas Jamieson. All Rights Reserved.
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://github.com/cartant/rxjs-tslint-rules
+ */
+/*tslint:disable:no-use-before-declare*/
+
+import * as Lint from "tslint";
+import * as ts from "typescript";
+
+import { UsedWalker } from "../support/used-walker";
+
+export class Rule extends Lint.Rules.TypedRule {
+
+    public static metadata: Lint.IRuleMetadata = {
+        description: "Disallows the use of the do operator.",
+        options: null,
+        optionsDescription: "Not configurable.",
+        requiresTypeInfo: true,
+        ruleName: "rxjs-no-do",
+        type: "style",
+        typescriptOnly: true
+    };
+
+    public static FAILURE_STRING = "RxJS do operator is forbidden";
+
+    public applyWithProgram(sourceFile: ts.SourceFile, program: ts.Program): Lint.RuleFailure[] {
+
+        return this.applyWithWalker(new Walker(sourceFile, this.getOptions(), program));
+    }
+}
+
+class Walker extends UsedWalker {
+
+    protected onSourceFileEnd(): void {
+
+        if (this.usedOperators["do"]) {
+            this.usedOperators["do"].forEach((node) => this.addFailureAtNode(node, Rule.FAILURE_STRING));
+        }
+    }
+}