YAML Handling Improvements (#1159)

PR turned out larger than I'd hoped but it covers significant ground:
* We no longer produce a minimal template for debugs targeting a template file.
* We still produce a temporary template, but it:
  * Uses all the fields from the old one aside from overwriting the handler name of the targeted function with any refs to parameters or parameter overrides
    * This is to accommodate the Python debug case, which requires a temporary shim file
  * The temporary template is now created as a sibling to the existing template file so the build can use relative pathing for any overrides
* Any parameters in the template file are now override-able through the `sam.template.parameters` field in the launch config.
* We now support `AWS::Lambda::Function`-type resources

As a side-effect, other template-related things (e.g. Lambda layers) should work after doing this. I haven't manually tested this yet.

We may want to consider how we handle the runtime, and handle it like the handler. As of now, if a runtime isn't explicitly provided (read: if it's provided as a ref to a parameter), the template won't validate. This is covered in a comment.

Author: bryceitoc9

package.json

@@ -307,13 +307,14 @@
                                         "type": "boolean"
                                     },
                                     "template": {
+                                        "description": "%AWS.configuration.description.awssam.debug.template%",
                                         "properties": {
                                             "parameters": {
+                                                "description": "%AWS.configuration.description.awssam.debug.templateParameters%",
                                                 "additionalProperties": {
                                                     "type": [
                                                         "string",
-                                                        "number",
-                                                        "boolean"
+                                                        "number"
                                                     ]
                                                 },
                                                 "type": "object"

package.nls.json

@@ -79,6 +79,8 @@
     "AWS.configuration.description.awssam.debug.dockerNetwork": "Specifies the name or id of an existing Docker network that Lambda Docker containers should connect to.",
     "AWS.configuration.description.awssam.debug.localArguments": "Additional arguments to pass to the `sam local` command.",
     "AWS.configuration.description.awssam.debug.skipNewImageCheck": "Specifies whether the command should skip pulling down the latest Docker image for Lambda runtime (default: false).",
+    "AWS.configuration.description.awssam.debug.template": "Values to override in the template",
+    "AWS.configuration.description.awssam.debug.templateParameters": "Key:value mappings for SAM template parameter overrides. More information can be found here: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/stackinstances-override.html#stackinstances-override-cli",
     "AWS.configuration.description.awssam.debug.snippets.lambdaCode.label": "AWS SAM: Direct Lambda handler invoke",
     "AWS.configuration.description.awssam.debug.snippets.lambdaCode.description": "A new configuration for invoking an AWS Lambda directly via the SAM CLI.",
     "AWS.configuration.description.awssam.debug.snippets.lambdaTemplate.label": "AWS SAM: Template-based Lambda invoke",
@@ -270,7 +272,7 @@
     "AWS.sam.debugger.missingTemplate": "Cannot find template file (must be workspace-relative, or absolute): {0}",
     "AWS.sam.debugger.missingResource": "Cannot find template resource \"{0}\" in template file: {1}",
     "AWS.sam.debugger.missingField": "Missing required field \"{0}\" in debug config",
-    "AWS.sam.debugger.resourceNotAFunction": "Template Resource {0} in Template file {1} needs to be of type {2}",
+    "AWS.sam.debugger.resourceNotAFunction": "Template Resource {0} in Template file {1} needs to be of type {2} or {3}",
     "AWS.sam.debugger.unsupportedRuntime": "Runtime for Template Resource {0} in Template file {1} is either undefined or unsupported.",
     "AWS.sam.debugger.useExistingConfig": "AWS Toolkit detected an existing legacy configuration for this function. Create the debug config based on the legacy config?",
     "AWS.sam.debugger.useExistingConfig.migrate": "Create based on the legacy config",

src/lambda/local/debugConfiguration.ts

@@ -88,13 +88,18 @@ export function getCodeRoot(
         }
         case 'template': {
             const templateInvoke = config.invokeTarget as TemplateTargetProperties
+            const template = getTemplate(folder, config)
+            if (!template) {
+                return undefined
+            }
             const templateResource = getTemplateResource(folder, config)
             if (!templateResource?.Properties) {
                 return undefined
             }
             const fullPath = tryGetAbsolutePath(folder, templateInvoke.templatePath)
             const templateDir = path.dirname(fullPath)
-            return pathutil.normalize(path.resolve(templateDir ?? '', templateResource?.Properties?.CodeUri))
+            const uri = CloudFormation.getStringForProperty(templateResource?.Properties?.CodeUri, template)
+            return uri ? pathutil.normalize(path.resolve(templateDir ?? '', uri)) : undefined
         }
         default: {
             throw Error('invalid invokeTarget') // Must not happen.
@@ -115,8 +120,17 @@ export function getHandlerName(
             return codeInvoke.lambdaHandler
         }
         case 'template': {
+            const template = getTemplate(folder, config)
+            if (!template) {
+                return ''
+            }
             const templateResource = getTemplateResource(folder, config)
-            return templateResource?.Properties?.Handler!!
+            const propertyValue = CloudFormation.resolvePropertyWithOverrides(
+                templateResource?.Properties?.Handler!!,
+                template,
+                config.sam?.template?.parameters
+            )
+            return propertyValue ? propertyValue.toString() : ''
         }
         default: {
             // Should never happen.

src/lambda/local/detectLocalLambdas.ts

@@ -62,14 +62,14 @@ async function detectLambdasFromTemplate(
             workspaceFolder,
             templatePath,
             templateGlobals: template.Globals,
-            handler: getHandler(resources[key]!),
+            handler: getHandler(resources[key]!, template),
             resource: resources[key]!,
         }))
 }
 
-function getHandler(resource: CloudFormation.Resource): string | undefined {
+function getHandler(resource: CloudFormation.Resource, template: CloudFormation.Template): string | undefined {
     if (resource.Properties && resource.Properties.Handler) {
-        return resource.Properties.Handler
+        return CloudFormation.getStringForProperty(resource.Properties.Handler, template)
     }
 
     return undefined