Add support for variable dependency (#242)

Fixes #203

Cargo.lock

@@ -89,7 +89,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "navi"
-version = "2.0.9"
+version = "2.0.10"
 dependencies = [
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "raw_tty 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "navi"
-version = "2.0.9"
+version = "2.0.10"
 authors = ["Denis Isidoro <denis_isidoro@live.com>"]
 edition = "2018"
 

README.md

@@ -30,6 +30,7 @@ Table of contents
    * [Cheatsheet syntax](#cheatsheet-syntax)
       * [Syntax overview](#syntax-overview)
       * [Variables](#variables)
+      * [Variable dependency](#variable-dependency)
       * [Variable options](#variable-options)
          * [Table formatting](#table-formatting)
          * [Multiple choice](#multiple-choice)
@@ -162,6 +163,17 @@ The interface prompts for variable names inside brackets (eg `<branch>`).
 
 Variable names should only include alphanumeric characters and `_`.
 
+### Variable dependency
+
+The command for generating possible inputs can refer other variables:
+```sh
+# If you select 2 for x, the possible values of y will be 12 and 22
+echo <x> <y>
+
+$ x: echo -e '1\n2\n3'
+$ y: echo -e "$((x+10))\n$((x+20))"
+```
+
 ### Variable options
 
 For lines starting with `$` you can add extra options using `---`.

src/cmds/core.rs

@@ -55,11 +55,22 @@ fn extract_from_selections(raw_output: &str, contains_key: bool) -> (&str, &str,
     (key, tags, snippet)
 }
 
-fn prompt_with_suggestions(config: &Config, suggestion: &cheat::Value) -> String {
+fn prompt_with_suggestions(
+    config: &Config,
+    suggestion: &cheat::Value,
+    values: &HashMap<String, String>,
+) -> String {
+    let mut vars_cmd = String::from("");
+    for (k, v) in values.iter() {
+        vars_cmd.push_str(format!("{}=\"{}\"; ", k, v).as_str());
+    }
+
+    let cmd = format!("{vars} {cmd}", vars = vars_cmd, cmd = &suggestion.0);
+
     let child = Command::new("bash")
         .stdout(Stdio::piped())
         .arg("-c")
-        .arg(&suggestion.0)
+        .arg(cmd)
         .spawn()
         .unwrap();
 
@@ -117,9 +128,9 @@ fn prompt_without_suggestions(varname: &str) -> String {
 
 fn gen_replacement(value: &str) -> String {
     if value.contains(' ') {
-        format!("\"{}\"", &value[..value.len() - 1])
+        format!("\"{}\"", value)
     } else {
-        value[..value.len() - 1].to_string()
+        value.to_string()
     }
 }
 
@@ -130,6 +141,7 @@ fn replace_variables_from_snippet(
     config: &Config,
 ) -> String {
     let mut interpolated_snippet = String::from(snippet);
+    let mut values: HashMap<String, String> = HashMap::new();
 
     let re = Regex::new(r"<(\w[\w\d\-_]*)>").unwrap();
     for cap in re.captures_iter(snippet) {
@@ -138,10 +150,12 @@ fn replace_variables_from_snippet(
         let k = format!("{};{}", tags, varname);
 
         let value = match variables.get(&k[..]) {
-            Some(suggestion) => prompt_with_suggestions(&config, suggestion),
+            Some(suggestion) => prompt_with_suggestions(&config, suggestion, &values),
             None => prompt_without_suggestions(varname),
         };
 
+        values.insert(varname.to_string(), value.clone());
+
         interpolated_snippet =
             interpolated_snippet.replace(bracketed_varname, gen_replacement(&value[..]).as_str());
     }

src/fzf.rs

@@ -123,7 +123,7 @@ where
 
     let out = child.wait_with_output().unwrap();
 
-    let text = match out.status.code() {
+    let mut text = match out.status.code() {
         Some(0) | Some(1) => String::from_utf8(out.stdout).unwrap(),
         Some(130) => process::exit(130),
         _ => {
@@ -132,6 +132,7 @@ where
             panic!("External command failed:\n {}", err)
         }
     };
+    text.truncate(text.len() - 1);
 
     (text, result)
 }