feat(scope): Add allowSubscribe option.

Closes #100.

package.json

@@ -78,7 +78,7 @@
     "test": "yarn run lint && yarn run test:build && yarn run test:mocha && yarn run test:tslint-v5 && yarn run test:tslint-v6 && yarn run test:tslint-v6-compat",
     "test:build": "yarn run test:clean && tsc -p tsconfig.json",
     "test:clean": "rimraf build",
-    "test:debug": "tslint --test \"./test/v6/fixtures/no-unsafe-scope/default/tslint.json\"",
+    "test:debug": "tslint --test \"./test/v6/fixtures/no-unsafe-scope/disallow/tslint.json\"",
     "test:issues": "yarn run test:clean && tsc -p tsconfig.json && tslint --test \"./test/v6/fixtures/issues/**/tslint.json\"",
     "test:mocha": "mocha \"./build/**/*-spec.js\"",
     "test:tslint-v5": "yarn --cwd ./test/v5 install && yarn --cwd ./test/v5 upgrade && tslint --test \"./test/v5/fixtures/**/tslint.json\"",

source/rules/rxjsNoUnsafeScopeRule.ts

@@ -88,9 +88,14 @@ class Walker extends ScopeWalker {
         options.allowProperties !== undefined
           ? options.allowProperties
           : this.allowProperties;
+      this.allowSubscribe =
+        options.allowSubscribe !== undefined
+          ? options.allowSubscribe
+          : this.allowSubscribe;
       this.allowTap =
         options.allowTap !== undefined ? options.allowTap : this.allowTap;
     }
+    this.knownNames = this.allowSubscribe ? {} : { subscribe: true };
   }
 
   protected visitNode(node: ts.Node): void {

source/support/scope-walker.ts

@@ -11,6 +11,7 @@ import { knownOperators, knownPipeableOperators } from "./knowns";
 export class ScopeWalker extends Lint.ProgramAwareRuleWalker {
   protected callbackMap: Map<ts.Node, string> = new Map<ts.Node, string>();
   protected callbackStack: (ts.ArrowFunction | ts.FunctionExpression)[] = [];
+  protected knownNames: Record<string, boolean> = {};
 
   protected visitArrowFunction(node: ts.ArrowFunction): void {
     if (this.callbackMap.has(node)) {
@@ -33,7 +34,12 @@ export class ScopeWalker extends Lint.ProgramAwareRuleWalker {
       name = propertyName.getText();
     }
 
-    if (name && (knownOperators[name] || knownPipeableOperators[name])) {
+    if (
+      name &&
+      (this.knownNames[name] ||
+        knownOperators[name] ||
+        knownPipeableOperators[name])
+    ) {
       const callbacks = args.filter(
         arg => tsutils.isArrowFunction(arg) || tsutils.isFunctionExpression(arg)
       );