Merge pull request #63 from yashptel/main

Fix: Support fallback values for `${param:x, fallback}` syntax in stage parameters

Author: mnapoli

lib/configuration/variables/sources/instance-dependent/param.js

@@ -63,16 +63,8 @@ module.exports = (serverlessInstance) => {
 
       const params = await resolveParams(stage, serverlessInstance);
       const value = params[address] ? params[address].value : null;
-      const result = { value };
 
-      if (value == null) {
-        throw new ServerlessError(
-          `The param "${address}" cannot be resolved from stage params. If you are using Serverless Framework Compose, make sure to run commands via Compose so that all parameters can be resolved`,
-          'MISSING_PARAM_SOURCE_ADDRESS'
-        );
-      }
-
-      return result;
+      return { value };
     },
   };
 };

test/unit/lib/configuration/variables/sources/instance-dependent/param.test.js

@@ -29,6 +29,7 @@ describe('test/unit/lib/configuration/variables/sources/instance-dependent/param
         unsupportedAddress: '${param:foo}',
         nonStringAddress: '${param:${self:custom.someObject}}',
         someObject: {},
+        variableWithFallback: '${param:bar, "value"}',
       },
       params: stageParameters,
     };
@@ -145,7 +146,7 @@ describe('test/unit/lib/configuration/variables/sources/instance-dependent/param
   it('should report with an error when the address is not supported', async () => {
     const { variablesMeta } = await runServerless();
     expect(variablesMeta.get('custom\0unsupportedAddress').error.code).to.equal(
-      'VARIABLE_RESOLUTION_ERROR'
+      'MISSING_VARIABLE_RESULT'
     );
   });
 
@@ -164,4 +165,14 @@ describe('test/unit/lib/configuration/variables/sources/instance-dependent/param
     expect(variablesMeta.get('provider\0timeout')).to.have.property('variables');
     expect(variablesMeta.get('provider\0timeout')).to.not.have.property('error');
   });
+
+  it('should substitute parameter when provided', async () => {
+    const { configuration } = await runServerless({ cliParameters: ['bar=qux'] });
+    expect(configuration.custom.variableWithFallback).to.equal('qux');
+  });
+
+  it('should use fallback when parameter is missing', async () => {
+    const { configuration } = await runServerless();
+    expect(configuration.custom.variableWithFallback).to.equal('value');
+  });
 });