Repository: serverless/serverless (JavaScript) — Bug Fix

Issue:
Default values don't work in variables within ${file}
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# This is a Bug Report

## Description

After updating to serverless 1.37 our serverless.yml (almost) silently stopped setting environment to lambdas. The issue ended up being related to default values of variables when including external files.

Here is an example config:

```
service: my-service

custom:
  config: ${file(config/${opt:stage, 'development'}.yml)}

provider:
  name: aws
  stage: ${self:custom.stage}
  environment: ${self:custom.config.environment}
```

The output of `sls print -s production` is:

```
service: my-service
custom:
  config:
    environment:
      IS_PRODUCTION: 'True'
provider:
  stage: production
  name: aws
```

Additionally, serverless shows a warning: `A valid service attribute to satisfy the declaration 'self:custom.config.environment' could not be found.`

If I remove the default value for `opt:stage` and use the following config, the problem disappears:

```
sls print -s production

service: my-service
custom:
  config:
    environment:
      IS_PRODUCTION: 'True'
provider:
  stage: production
  name: aws
  environment: <<< ENVIRONMENT IS PRESENT NOW
     $ref: '$["custom"]["config"]["environment"]'
```

The same config (with the default value) works just fine with `serverless@1.36.3`.


Discussion:

Resolving patch:
diff --git a/lib/classes/Variables.js b/lib/classes/Variables.js
index 6d81ab4bfdc..ef1b4f829b6 100644
--- a/lib/classes/Variables.js
+++ b/lib/classes/Variables.js
@@ -785,7 +785,7 @@ class Variables {
       index = this.deep.push(variable) - 1;
     }
     const variableContainer = variable.match(this.variableSyntax)[0];
-    const variableString = this.cleanVariable(variableContainer);
+    const variableString = this.cleanVariable(variableContainer).replace(/\s/g, '');
     return variableContainer
       .replace(/\s/g, '')
       .replace(variableString, `deep:${index}`);


Test patch:
diff --git a/lib/classes/Variables.test.js b/lib/classes/Variables.test.js
index e6e3dfdb1d4..f49356cc1b5 100644
--- a/lib/classes/Variables.test.js
+++ b/lib/classes/Variables.test.js
@@ -945,6 +945,23 @@ module.exports = {
           return serverless.variables.populateObject(service.custom)
             .should.become(expected);
         });
+        it('should still work with a default file name in double or single quotes', () => {
+          makeTempFile(asyncFileName, asyncContent);
+          service.custom = {
+            val1: '${self:custom.val0}', // eslint-disable-line no-template-curly-in-string
+            val2: '${self:custom.val1}', // eslint-disable-line no-template-curly-in-string
+            val3: `\${file(\${self:custom.nonexistent, "${asyncFileName}"}):str}`,
+            val0: `\${file(\${self:custom.nonexistent, '${asyncFileName}'}):str}`,
+          };
+          const expected = {
+            val1: 'my-async-value-1',
+            val2: 'my-async-value-1',
+            val3: 'my-async-value-1',
+            val0: 'my-async-value-1',
+          };
+          return serverless.variables.populateObject(service.custom)
+            .should.become(expected);
+        });
         it('should populate any given variable only once regardless of ordering or reference count',
           () => {
             makeTempFile(asyncFileName, asyncContent);
@@ -997,8 +1014,8 @@ module.exports = {
           () => {
             const fileName = `./node_modules/@scoped-org/${asyncFileName}`;
             makeTempFile(
-                fileName,
-                asyncContent
+              fileName,
+              asyncContent
             );
             service.custom = {
               val0: `\${file(${fileName}):str}`,
@@ -1007,8 +1024,8 @@ module.exports = {
               val0: 'my-async-value-1',
             };
             return serverless.variables
-                .populateObject(service.custom)
-                .should.become(expected);
+              .populateObject(service.custom)
+              .should.become(expected);
           });
         const selfFileName = 'self.yml';
         const selfContent = `foo: baz