Add --maskfile-introspect flag to print out the maskfile command stru…

…cture as json (#85)

* Add --maskfile-introspect flag to print out command structure in json format

* Add test for --maskfile-introspect

mask/Cargo.toml

@@ -12,6 +12,7 @@ license = "MIT"
 
 [dependencies]
 colored = "2"                                                           # https://github.com/mackwic/colored
+serde_json = "1.0"                                                      # https://github.com/serde-rs/json
 mask-parser = { path = "../mask-parser" }
 
 [dependencies.clap]                                                     # https://github.com/clap-rs/clap

mask/src/main.rs

@@ -14,7 +14,8 @@ fn main() {
         .setting(AppSettings::SubcommandRequired)
         .setting(AppSettings::ColoredHelp)
         .version(crate_version!())
-        .arg(custom_maskfile_path_arg());
+        .arg(custom_maskfile_path_arg())
+        .arg(introspect_arg());
 
     let (maskfile, maskfile_path) = find_maskfile();
     if maskfile.is_err() {
@@ -24,6 +25,13 @@ fn main() {
     }
 
     let root = mask_parser::parse(maskfile.unwrap());
+
+    if is_introspecting() {
+        let json = root.to_json().expect("to_json failed");
+        println!("{}", serde_json::to_string_pretty(&json).unwrap());
+        return;
+    }
+
     let matches = build_subcommands(cli_app, &root.commands).get_matches();
     let chosen_cmd =
         find_command(&matches, &root.commands).expect("SubcommandRequired failed to work");
@@ -71,17 +79,34 @@ fn find_maskfile() -> (Result<String, String>, String) {
     (maskfile, maskfile_path.to_str().unwrap().to_string())
 }
 
+fn is_introspecting() -> bool {
+    let args: Vec<String> = env::args().collect();
+    for a in args {
+        if a == "--maskfile-introspect" {
+            return true;
+        }
+    }
+    false
+}
+
+/// Load a maskfile from another directory
 fn custom_maskfile_path_arg<'a, 'b>() -> Arg<'a, 'b> {
     // This is needed to prevent clap from complaining about the custom flag check
     // within find_maskfile(). It should be removed once clap 3.x is released.
     // See https://github.com/clap-rs/clap/issues/748
-    let custom_maskfile_path = Arg::with_name("maskfile")
+    Arg::with_name("maskfile")
         .help("Path to a different maskfile you want to use")
         .long("maskfile")
         .takes_value(true)
-        .multiple(false);
+        .multiple(false)
+}
 
-    custom_maskfile_path
+/// Print out the maskfile structure in json
+fn introspect_arg<'a, 'b>() -> Arg<'a, 'b> {
+    Arg::with_name("maskfile-introspect")
+        .help("Print out the maskfile command structure in json")
+        .long("maskfile-introspect")
+        .multiple(false)
 }
 
 fn build_subcommands<'a, 'b>(

mask/tests/introspect_test.rs

@@ -0,0 +1,59 @@
+mod common;
+use assert_cmd::prelude::*;
+use predicates::str::contains;
+use serde_json::json;
+
+#[test]
+fn outputs_the_maskfile_structure_as_json() {
+    let (_temp, maskfile_path) = common::maskfile(
+        r#"
+# Document Title
+
+## somecommand
+> The command description
+
+~~~bash
+echo something
+~~~
+"#,
+    );
+
+    let verbose_flag = json!({
+        "name": "verbose",
+        "description": "Sets the level of verbosity",
+        "short": "v",
+        "long": "verbose",
+        "multiple": false,
+        "takes_value": false,
+        "required": false,
+        "validate_as_number": false,
+    });
+
+    let expected_json = json!({
+        "title": "Document Title",
+        "description": "",
+        "commands": [
+            {
+                "level": 2,
+                "name": "somecommand",
+                "description": "The command description",
+                "script": {
+                    "executor": "bash",
+                    "source": "echo something\n",
+                },
+                "subcommands": [],
+                "required_args": [],
+                "named_flags": [verbose_flag],
+            }
+        ]
+    });
+
+    common::run_mask(&maskfile_path)
+        .arg("--maskfile-introspect")
+        .assert()
+        .code(0)
+        .stdout(contains(
+            serde_json::to_string_pretty(&expected_json).unwrap(),
+        ))
+        .success();
+}