feat: Allow directory truncation length to be configured (#120)

This allows the directory truncation length to be configured. Previously, it was hard-coded to truncate to 3 parent directories.

docs/config/README.md

@@ -117,9 +117,19 @@ git repo that you're currently in.
 ### Options
 
 | Variable            | Default | Description                            |
-| ---------- | ------- | -------------------------------- |
+| ------------------- | ------- | -------------------------------------- |
+| `truncation_length` | `3`     | Truncates to this many parent folders. |
 | `disabled`          | `false` | Disables the `directory` module.       |
 
+### Example
+
+```toml
+# ~/.config/starship.toml
+
+[directory]
+truncation_length = 8
+```
+
 ## Git Branch
 
 The `git_branch` module shows the active branch of the repo in your current directory.

src/config.rs

@@ -12,6 +12,7 @@ pub trait Config {
     // Config accessor methods
     fn get_as_bool(&self, key: &str) -> Option<bool>;
     fn get_as_str(&self, key: &str) -> Option<&str>;
+    fn get_as_i64(&self, key: &str) -> Option<i64>;
 
     // Internal implementation for accessors
     fn get_config(&self, key: &str) -> Option<&toml::value::Value>;
@@ -129,6 +130,23 @@ impl Config for Table {
 
         str_value
     }
+
+    /// Get a key from a module's configuration as an integer
+    fn get_as_i64(&self, key: &str) -> Option<i64> {
+        let value = self.get_config(key)?;
+        let i64_value = value.as_integer();
+
+        if i64_value.is_none() {
+            log::debug!(
+                "Expected \"{}\" to be an integer. Instead received {} of type {}.",
+                key,
+                value,
+                value.type_str()
+            );
+        }
+
+        i64_value
+    }
 }
 
 mod tests {
@@ -165,4 +183,20 @@ mod tests {
         table.insert(String::from("boolean"), toml::value::Value::Boolean(true));
         assert_eq!(table.get_as_str("boolean"), None);
     }
+
+    #[test]
+    fn table_get_as_i64() {
+        let mut table = toml::value::Table::new();
+
+        // Use with integer value
+        table.insert(String::from("integer"), toml::value::Value::Integer(82));
+        assert_eq!(table.get_as_i64("integer"), Some(82));
+
+        // Use with string value
+        table.insert(
+            String::from("string"),
+            toml::value::Value::String(String::from("82")),
+        );
+        assert_eq!(table.get_as_bool("string"), None);
+    }
 }

src/module.rs

@@ -99,6 +99,16 @@ impl<'a> Module<'a> {
     fn config_value(&self, key: &str) -> Option<&str> {
         self.config.and_then(|config| config.get_as_str(key))
     }
+
+    /// Get a module's config value as an int
+    pub fn config_value_i64(&self, key: &str) -> Option<i64> {
+        self.config.and_then(|config| config.get_as_i64(key))
+    }
+
+    /// Get a module's config value as a bool
+    pub fn config_value_bool(&self, key: &str) -> Option<bool> {
+        self.config.and_then(|config| config.get_as_bool(key))
+    }
 }
 
 impl<'a> fmt::Display for Module<'a> {

src/modules/directory.rs

@@ -15,12 +15,16 @@ use super::{Context, Module};
 /// Paths will be limited in length to `3` path components by default.
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     const HOME_SYMBOL: &str = "~";
-    const DIR_TRUNCATION_LENGTH: usize = 3;
+    const DIR_TRUNCATION_LENGTH: i64 = 3;
     let module_color = Color::Cyan.bold();
 
     let mut module = context.new_module("directory")?;
     module.set_style(module_color);
 
+    let truncation_length = module
+        .config_value_i64("truncation_length")
+        .unwrap_or(DIR_TRUNCATION_LENGTH);
+
     let current_dir = &context.current_dir;
     log::debug!("Current directory: {:?}", current_dir);
 
@@ -38,7 +42,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     // Truncate the dir string to the maximum number of path components
-    let truncated_dir_string = truncate(dir_string, DIR_TRUNCATION_LENGTH);
+    let truncated_dir_string = truncate(dir_string, truncation_length as usize);
     module.new_segment("path", &truncated_dir_string);
 
     module.get_prefix().set_value("in ");

tests/testsuite/directory.rs

@@ -6,7 +6,7 @@ use std::io;
 use std::path::Path;
 use tempfile::TempDir;
 
-use crate::common;
+use crate::common::{self, TestCommand};
 
 #[test]
 fn home_directory() -> io::Result<()> {
@@ -95,6 +95,51 @@ fn truncated_directory_in_root() -> io::Result<()> {
     Ok(())
 }
 
+#[test]
+#[ignore]
+fn truncated_directory_config_large() -> io::Result<()> {
+    let dir = Path::new("/tmp/starship/thrusters/rocket");
+    fs::create_dir_all(&dir)?;
+
+    let output = common::render_module("dir")
+        .use_config(toml::toml! {
+            [directory]
+            truncation_length = 100
+        })
+        .arg("--path")
+        .arg(dir)
+        .output()?;
+    let actual = String::from_utf8(output.stdout).unwrap();
+
+    let expected = format!(
+        "in {} ",
+        Color::Cyan.bold().paint("/tmp/starship/thrusters/rocket")
+    );
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+#[ignore]
+fn truncated_directory_config_small() -> io::Result<()> {
+    let dir = Path::new("/tmp/starship/thrusters/rocket");
+    fs::create_dir_all(&dir)?;
+
+    let output = common::render_module("dir")
+        .use_config(toml::toml! {
+            [directory]
+            truncation_length = 2
+        })
+        .arg("--path")
+        .arg(dir)
+        .output()?;
+    let actual = String::from_utf8(output.stdout).unwrap();
+
+    let expected = format!("in {} ", Color::Cyan.bold().paint("thrusters/rocket"));
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
 #[test]
 #[ignore]
 fn git_repo_root() -> io::Result<()> {