fix: Include trailing slash when passing empty query parameters.

lib/StripeResource.js

@@ -69,30 +69,42 @@ StripeResource.prototype = {
   validateRequest: null,
 
   createFullPath(commandPath, urlData) {
-    return this._joinUrlParts([
-      this.basePath(urlData),
-      this.path(urlData),
-      typeof commandPath == 'function' ? commandPath(urlData) : commandPath,
-    ]);
+    const urlParts = [this.basePath(urlData), this.path(urlData)];
+
+    if (typeof commandPath === 'function') {
+      const computedCommandPath = commandPath(urlData);
+      // If we have no actual command path, we just omit it to avoid adding a
+      // trailing slash. This is important for top-level listing requests, which
+      // do not have a command path.
+      if (computedCommandPath) {
+        urlParts.push(computedCommandPath);
+      }
+    } else {
+      urlParts.push(commandPath);
+    }
+
+    return this._joinUrlParts(urlParts);
   },
 
   // Creates a relative resource path with symbols left in (unlike
   // createFullPath which takes some data to replace them with). For example it
   // might produce: /invoices/{id}
   createResourcePathWithSymbols(pathWithSymbols) {
-    return `/${this._joinUrlParts([this.resourcePath, pathWithSymbols || ''])}`;
+    // If there is no path beyond the resource path, we want to produce just
+    // /<resource path> rather than /<resource path>/.
+    if (pathWithSymbols) {
+      return `/${this._joinUrlParts([this.resourcePath, pathWithSymbols])}`;
+    } else {
+      return `/${this.resourcePath}`;
+    }
   },
 
   _joinUrlParts(parts) {
     // Replace any accidentally doubled up slashes. This previously used
     // path.join, which would do this as well. Unfortunately we need to do this
     // as the functions for creating paths are technically part of the public
     // interface and so we need to preserve backwards compatibility.
-    const path = parts.join('/').replace(/\/{2,}/g, '/');
-
-    // If the path ends with a /, we preserve the behavior of path.join and
-    // strip off the trailing / (eg. /v1/customers/ -> /v1/customers).
-    return path.endsWith('/') ? path.slice(0, -1) : path;
+    return parts.join('/').replace(/\/{2,}/g, '/');
   },
 
   // DEPRECATED: Here for backcompat in case users relied on this.

lib/makeRequest.js

@@ -52,6 +52,7 @@ function getRequestOpts(self, requestArgs, spec, overrideData) {
   const requestPath = isUsingFullPath
     ? commandPath(urlData)
     : self.createFullPath(commandPath, urlData);
+
   const headers = Object.assign(options.headers, spec.headers);
 
   if (spec.validator) {

test/StripeResource.spec.js

@@ -22,12 +22,19 @@ const {
 
 describe('StripeResource', () => {
   describe('createResourcePathWithSymbols', () => {
-    it('Generates a path', () => {
+    it('Generates a path when there is a symbol', () => {
       stripe.invoices.create({});
       const path = stripe.invoices.createResourcePathWithSymbols('{id}');
       expect(path).to.equal('/invoices/{id}');
     });
 
+    it('Generates a path when there is nothing beyond the resource path', () => {
+      stripe.invoices.create({});
+      const path = stripe.invoices.createResourcePathWithSymbols('');
+      // This explicitly shouldn't have a trailing slash.
+      expect(path).to.equal('/invoices');
+    });
+
     it('Handles accidental double slashes', () => {
       stripe.invoices.create({});
       const path = stripe.invoices.createResourcePathWithSymbols('/{id}');
@@ -36,9 +43,9 @@ describe('StripeResource', () => {
   });
 
   describe('_joinUrlParts', () => {
-    it('handles trailing empty values correctly', () => {
+    it('includes trailing empty values', () => {
       const path = stripe.invoices._joinUrlParts(['a', '']);
-      expect(path).to.equal('a');
+      expect(path).to.equal('a/');
     });
 
     it('joins parts', () => {
@@ -132,6 +139,72 @@ describe('StripeResource', () => {
         });
       });
 
+      it('handles .. as a query param', (done) => {
+        const scope = nock(`https://${stripe.getConstant('DEFAULT_HOST')}`)
+          .get('/v1/customers/..', '')
+          .reply(200, '{}');
+
+        realStripe.customers.retrieve('..', (err, response) => {
+          done(err);
+          scope.done();
+        });
+      });
+
+      it('handles empty string as a query param', (done) => {
+        const scope = nock(`https://${stripe.getConstant('DEFAULT_HOST')}`)
+          // Note this should always have a trailing space to avoid calling the
+          // top level list endpoint (/v1/customers) and returning all customers.
+          .get('/v1/customers/', '')
+          .reply(200, '{}');
+
+        realStripe.customers.retrieve('', (err, response) => {
+          done(err);
+          scope.done();
+        });
+      });
+
+      it('handles empty string as a query param for namespaced resources', (done) => {
+        const scope = nock(`https://${stripe.getConstant('DEFAULT_HOST')}`)
+          // Note this should always have a trailing space to avoid calling the
+          // top level list endpoint (/v1/customers) and returning all customers.
+          .get('/v1/checkout/sessions/', '')
+          .reply(200, '{}');
+
+        realStripe.checkout.sessions.retrieve('', (err, response) => {
+          done(err);
+          scope.done();
+        });
+      });
+
+      it('handles empty string as a query param for nested resources', (done) => {
+        const scope = nock(`https://${stripe.getConstant('DEFAULT_HOST')}`)
+          // Note this should always have a trailing space to avoid calling the
+          // top level list endpoint (/v1/customers) and returning all customers.
+          .get('/v1/customers/cus_123/balance_transactions/', '')
+          .reply(200, '{}');
+
+        realStripe.customers.retrieveBalanceTransaction(
+          'cus_123',
+          '',
+          (err, response) => {
+            done(err);
+            scope.done();
+          }
+        );
+      });
+
+      it('does not include trailing slash for endpoints without query parameters', (done) => {
+        const scope = nock(`https://${stripe.getConstant('DEFAULT_HOST')}`)
+          // Note that no trailing slash is present.
+          .get('/v1/customers', '')
+          .reply(200, '{}');
+
+        realStripe.customers.list((err, response) => {
+          done(err);
+          scope.done();
+        });
+      });
+
       it('works correctly with undefined optional arguments', (done) => {
         const scope = nock(`https://${stripe.getConstant('DEFAULT_HOST')}`)
           .get('/v1/accounts/acct_123')