feat: resolve variables in vars declarations too

docs/docs/experiments/any_variables.mdx

@@ -179,12 +179,12 @@ tasks:
       - 'echo {{.FOO.b}}'
 ```
 
-## Parsing variables by reference
+## Variables by reference
 
-Lastly, this proposal adds support for parsing variables by reference. This is
+Lastly, this proposal adds support for defining and passing variables by
-really important now that variables can be types other than a string.
+reference. This is really important now that variables can be types other than a
-Previously, to send a variable from one task to another, you would have to use
+string. Previously, to send a variable from one task to another, you would have
-the templating system to pass it:
+to use the templating system to pass it:
 
 ```yaml
 version: 3
@@ -225,7 +225,20 @@ tasks:
 ```
 
 This means that the type of the variable is maintained when it is passed to
-another Task.
+another Task. This also works when defining a variable:
+
+```yaml
+version: 3
+
+tasks:
+  foo:
+    vars:
+      FOO: [A, B, C] # <-- FOO is defined as an array
+      BAR:
+        ref: FOO # <-- BAR is defined as a reference to FOO
+    cmds:
+      - 'echo {{index .BAR 0}}' # <-- BAR refers to FOO so the task outputs 'A'
+```
 
 </TabItem></Tabs>
 

internal/compiler/compiler.go

@@ -71,6 +71,10 @@ func (c *Compiler) getVariables(t *ast.Task, call *ast.Call, evaluateShVars bool
 			newVar.Json = tr.Replace(v.Json)
 			newVar.Yaml = tr.Replace(v.Yaml)
 			newVar.Dir = v.Dir
+			// If the variable is a reference, we can resolve it
+			if newVar.Ref != "" {
+				newVar.Value = result.Get(newVar.Ref).Value
+			}
 			// If the variable should not be evaluated, but is nil, set it to an empty string
 			// This stops empty interface errors when using the templater to replace values later
 			if !evaluateShVars && newVar.Value == nil {

testdata/vars/any2/Taskfile.yml

@@ -16,6 +16,32 @@ tasks:
           VAR:
             ref: MAP
 
+  map-ref:
+    vars:
+      MAP:
+        map: {"name":"Alice","age":30,"children":[{"name":"Bob","age":5},{"name":"Charlie","age":3},{"name":"Diane","age":1}]}
+      MAP_REF:
+        ref: MAP
+    cmds:
+      - task: print-var
+        vars:
+          VAR:
+            ref: MAP_REF
+
+  map-ref-sh:
+    vars:
+      JSON_STRING:
+        sh: echo '{"name":"Alice","age":30,"children":[{"name":"Bob","age":5},{"name":"Charlie","age":3},{"name":"Diane","age":1}]}'
+      JSON:
+        json: "{{.JSON_STRING}}"
+      MAP_REF:
+        ref: JSON
+    cmds:
+      - task: print-var
+        vars:
+          VAR:
+            ref: MAP_REF
+
   json:
     vars:
       JSON_STRING: