feat: Add Environment Variable module (#409)

tests/testsuite/env_var.rs

@@ -0,0 +1,141 @@
+use ansi_term::{Color, Style};
+use std::io;
+
+use crate::common;
+use crate::common::TestCommand;
+
+const TEST_VAR_VALUE: &str = "astronauts";
+
+#[test]
+fn empty_config() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+        })
+        .output()?;
+    let expected = "";
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn defined_variable() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+            variable = "TEST_VAR"
+        })
+        .env("TEST_VAR", TEST_VAR_VALUE)
+        .output()?;
+    let expected = format!("with {} ", style().paint(TEST_VAR_VALUE));
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn undefined_variable() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+            variable = "TEST_VAR"
+        })
+        .output()?;
+    let expected = "";
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn default_has_no_effect() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+            variable = "TEST_VAR"
+            default = "N/A"
+        })
+        .env("TEST_VAR", TEST_VAR_VALUE)
+        .output()?;
+    let expected = format!("with {} ", style().paint(TEST_VAR_VALUE));
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn default_takes_effect() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+            variable = "UNDEFINED_TEST_VAR"
+            default = "N/A"
+        })
+        .output()?;
+    let expected = format!("with {} ", style().paint("N/A"));
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn symbol() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+            symbol = "■ "
+            variable = "TEST_VAR"
+        })
+        .env("TEST_VAR", TEST_VAR_VALUE)
+        .output()?;
+    let expected = format!("with {} ", style().paint(format!("■ {}", TEST_VAR_VALUE)));
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn prefix() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+            variable = "TEST_VAR"
+            prefix = "_"
+        })
+        .env("TEST_VAR", TEST_VAR_VALUE)
+        .output()?;
+    let expected = format!("with {} ", style().paint(format!("_{}", TEST_VAR_VALUE)));
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+#[test]
+fn suffix() -> io::Result<()> {
+    let output = common::render_module("env_var")
+        .env_clear()
+        .use_config(toml::toml! {
+            [env_var]
+            variable = "TEST_VAR"
+            suffix = "_"
+        })
+        .env("TEST_VAR", TEST_VAR_VALUE)
+        .output()?;
+    let expected = format!("with {} ", style().paint(format!("{}_", TEST_VAR_VALUE)));
+    let actual = String::from_utf8(output.stdout).unwrap();
+    assert_eq!(expected, actual);
+    Ok(())
+}
+
+fn style() -> Style {
+    // default style
+    Color::Black.bold().dimmed()
+}