Improve inject_global_rule to allow structured data

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Changelog
 
+* improve `inject_global_value` to support structured data. Add the `env_json` property to inject JSON encoded data and the `default_value` property to inject data when the provided environment variable is not defined ([#277](https://github.com/seaofvoices/darklua/pull/277))
 * add rule to remove method call syntax (`remove_method_call`) ([#276](https://github.com/seaofvoices/darklua/pull/276))
 * fix `remove_unused_variable` rule to correctly handle trailing unassigned (but used!) variables ([#275](https://github.com/seaofvoices/darklua/pull/275))
 * add rule to convert Luau numbers (`convert_luau_number`) ([#274](https://github.com/seaofvoices/darklua/pull/274))

Cargo.toml

@@ -35,6 +35,7 @@ full_moon = { version = "1.0.0", features = ["roblox"] }
 indexmap = "2.7.0"
 json5 = "0.4.1"
 log = "0.4.22"
+num-traits = "0.2.19"
 pathdiff = "0.2.3"
 petgraph = "0.6.5"
 regex = "1.11.1"

site/content/rules/inject_global_value.md

@@ -7,23 +7,46 @@ parameters:
     type: string
     description: The name of the global variable
   - name: value
-    type: boolean, number or string
+    type: any
     description: The value to inject
     default: nil
   - name: env
     added_in: "0.7.0"
     type: string
     description: An environment variable to read the value from
+  - name: env_json
+    added_in: "unreleased"
+    type: string
+    description: An environment variable to read the json-encoded value from
+  - name: default_value
+    added_in: "unreleased"
+    type: any
+    description: The default value when using an environment variable that is not defined
 examples:
   - rules: "[{ rule: 'inject_global_value', identifier: 'CONSTANT', value: 'Hello' }, { rule: 'inject_global_value', identifier: 'AMOUNT', value: 11 }]"
     content: |
       if _G.AMOUNT > 10 or _G.CONSTANT ~= nil then
         --[[ ... ]]
       end
+  - rules: "[{ rule: 'inject_global_value', identifier: 'DEBUG', value: true }]"
+    content: |
+      if _G.DEBUG then
+        print('Debug information')
+      end
 ---
 
 This rule will find a global variable and replace it with a given value. The value can be defined in the rule configuration or taken from an environment variable.
 
+To inject a static value, use the `value` property.
+
+```json5
+{
+  rule: "inject_global_value",
+  identifier: "GLOBAL",
+  value: true,
+}
+```
+
 If `value` is not specified, the `env` property can be defined to read an environment variable that will be read into a string.
 
 ```json5
@@ -34,4 +57,25 @@ If `value` is not specified, the `env` property can be defined to read an enviro
 }
 ```
 
+Alternatively, the `env_json` property allows you to read a JSON-encoded value (`json5` is supported) from an environment variable. This is useful for injecting any data like booleans or structured data like arrays or objects.
+
+```json5
+{
+  rule: "inject_global_value",
+  identifier: "SETTINGS",
+  env_json: "APP_SETTINGS",
+}
+```
+
+When using the `env` or `env_json` property, the `default_value` property can be used to provide a fallback value when the environment variable is not defined. This prevents the rule from using `nil` as the default value.
+
+```json5
+{
+  rule: "inject_global_value",
+  identifier: "FEATURE_FLAG",
+  env: "ENABLE_FEATURE",
+  default_value: false,
+}
+```
+
 This rule can be used in combination with the `remove_unused_if_branch`, `compute_expression`, and other rules, to eliminate dead branches. In addition to making your code smaller, it should make it faster (depending on how hot the code path is) since it is eliminating branch condition evaluations at client-side runtime.