Always update connections.env and fix double-toggled connection line

Drop the --legacy flag: set_local_db and toggle_index now run
unconditionally instead of only when -l was passed, since that was the
flag's only effect.

Fix set_dot_env writing the connection/RCC_CONNECTION line twice with
opposing polarity (once from the #docker pass, once from the #cidb
pass), which flipped it to the wrong value. Collapsed the three
separate open/read/write passes into one, toggling both sections and
the connection line in a single scan so the connection line is only
ever touched once.

README.md

@@ -35,14 +35,13 @@ cargo install --path .
 ## Usage
 
 ```
-dev_tools <project> <up|down> [--legacy]
+dev_tools <project> <up|down>
 ```
 
 | Argument | Description |
 |---|---|
 | `project` | Project key (matches `<PROJECT>_DIR` in the config, case-insensitive) |
 | `up` / `down` | Start or stop the environment |
-| `-l`, `--legacy` | Enable legacy mode: also toggles `conf/global/connections.env` and runs `git update-index` |
 
 ### Examples
 
@@ -52,16 +51,13 @@ dev_tools foo up
 
 # Stop it
 dev_tools foo down
-
-# Start with legacy env handling
-dev_tools foo up --legacy
 ```
 
 ## What it does
 
 1. Starts or stops the Docker Compose service defined by `DOCKER_SERVICE` / `DOCKER_DIR`.
-2. Toggles database connection entries in `<PROJECT_DIR>/conf/local/.env` between `staging` and CI values.
+2. Modifies `conf/global/connections.env` and marks it with `git update-index --assume-unchanged` to avoid accidental commits.
-3. With `--legacy`: additionally modifies `conf/global/connections.env` and marks it with `git update-index --assume-unchanged` to avoid accidental commits.
+3. Toggles database connection entries in `<PROJECT_DIR>/conf/local/.env`: `up` switches the connection to `ci`, `down` switches it to `staging`.
 
 ## Tests
 

src/arguments.rs

@@ -13,13 +13,6 @@ pub struct Arguments {
 
     #[arg(help = "Possible values are 'up' and 'down'")]
     pub action: String,
-
-    #[arg(
-        short = 'l',
-        long = "legacy",
-        help = "Legacy mode for old env reading."
-    )]
-    pub legacy: bool,
 }
 
 impl Arguments {
@@ -40,7 +33,6 @@ mod tests {
         Arguments {
             project: "test".to_string(),
             action: action.to_string(),
-            legacy: false,
         }
     }
 

src/config/parse.rs

@@ -69,11 +69,81 @@ pub fn set_local_db(start: bool, config: &DevToolsConf) -> Result<FileChange> {
     })
 }
 
+const DOCKER_SECTION: &str = "#docker";
+const DOCKER_SECTION_LINES: usize = 4;
+const CIDB_SECTION: &str = "#cidb";
+const CIDB_SECTION_LINES: usize = 2;
+
+/// Toggles the `#docker` and `#cidb` sections and the `connection` line of
+/// `conf/local/.env` in a single read/write pass. `#docker` follows `start`
+/// directly; `#cidb` and the connection line follow its inverse (`up` means
+/// the local docker db is reachable, so `#cidb`'s CI credentials switch off
+/// and the connection moves to `ci`; `down` is the reverse, ending on
+/// `staging`). Every line outside both sections is checked against
+/// `connection_key` exactly once, so it can't be toggled twice.
 pub fn set_dot_env(start: bool, config: &DevToolsConf) -> Result<FileChange> {
-    let mut docker_change = toggle_after_line("#docker", 4, start, config)?;
+    let local_connection_env = format!(
-    let cidb_change = toggle_after_line("#cidb", 2, !start, config)?;
+        "{}{}",
-    docker_change.diffs.extend(cidb_change.diffs);
+        config.project_dir_as_string(),
-    Ok(docker_change)
+        LOCAL_CONNECTION_PATH
+    );
+    let file: File = File::open(&local_connection_env)
+        .with_context(|| format!("could not read file `{}`", local_connection_env))?;
+    let reader: BufReader<File> = BufReader::new(file);
+
+    let mut modified_lines: Vec<String> = Vec::new();
+    let mut diffs: Vec<(String, String)> = Vec::new();
+    let mut section: Option<(bool, usize)> = None;
+
+    for line in reader.lines() {
+        let line_content = line?;
+        let trimmed = line_content.trim_start();
+
+        if let Some((_, remaining)) = section {
+            if remaining == 0 {
+                section = None;
+            }
+        }
+
+        if trimmed.starts_with(DOCKER_SECTION) {
+            section = Some((start, DOCKER_SECTION_LINES));
+            modified_lines.push(line_content);
+            continue;
+        }
+        if trimmed.starts_with(CIDB_SECTION) {
+            section = Some((!start, CIDB_SECTION_LINES));
+            modified_lines.push(line_content);
+            continue;
+        }
+
+        let modified: Option<String> = if let Some((activate, remaining)) = &mut section {
+            let new_line = toggle(&line_content, *activate);
+            *remaining -= 1;
+            (new_line != line_content).then_some(new_line)
+        } else {
+            connection_key(&line_content).and_then(|key| {
+                let value = if start { "ci" } else { "staging" };
+                let new_line = format!("{}='{}'", key, value);
+                (new_line != line_content).then_some(new_line)
+            })
+        };
+
+        match modified {
+            Some(new_line) => {
+                diffs.push((line_content, new_line.clone()));
+                modified_lines.push(new_line);
+            }
+            None => modified_lines.push(line_content),
+        }
+    }
+
+    fs::write(&local_connection_env, modified_lines.join("\n"))
+        .context("Cannot write local connection env")?;
+
+    Ok(FileChange {
+        path: local_connection_env,
+        diffs,
+    })
 }
 
 const CI_DB_MASTER_IP: &str = "ci.db.master.ip";
@@ -112,68 +182,6 @@ pub(crate) fn should_commented_out(line: &str) -> bool {
     }
 }
 
-fn toggle_after_line(
-    target_line_prefix: &str,
-    num_lines: usize,
-    activate: bool,
-    config: &DevToolsConf,
-) -> Result<FileChange> {
-    let local_connection_env = format!(
-        "{}{}",
-        config.project_dir_as_string(),
-        LOCAL_CONNECTION_PATH
-    );
-    let file: File = File::open(&local_connection_env)
-        .with_context(|| format!("could not read file `{}`", local_connection_env))?;
-    let reader: BufReader<File> = BufReader::new(file);
-
-    let mut modified_lines: Vec<String> = Vec::new();
-    let mut diffs: Vec<(String, String)> = Vec::new();
-    let mut relevant = false;
-    let mut counter: usize = 0;
-
-    for line in reader.lines() {
-        let line_content = line?;
-
-        if counter == num_lines {
-            relevant = false;
-        }
-        if line_content.trim_start().starts_with(target_line_prefix) {
-            relevant = true;
-            modified_lines.push(line_content);
-            continue;
-        }
-
-        let modified: Option<String> = if relevant {
-            counter += 1;
-            let new_line = toggle(&line_content, activate);
-            (new_line != line_content).then_some(new_line)
-        } else if let Some(key) = connection_key(&line_content) {
-            let value = if activate { "staging" } else { "ci" };
-            let new_line = format!("{}='{}'", key, value);
-            (new_line != line_content).then_some(new_line)
-        } else {
-            None
-        };
-
-        match modified {
-            Some(new_line) => {
-                diffs.push((line_content, new_line.clone()));
-                modified_lines.push(new_line);
-            }
-            None => modified_lines.push(line_content),
-        }
-    }
-
-    fs::write(&local_connection_env, modified_lines.join("\n"))
-        .context("Cannot write local connection env")?;
-
-    Ok(FileChange {
-        path: local_connection_env,
-        diffs,
-    })
-}
-
 /// Returns the `connection` key as it appears on the given line (either the
 /// legacy `connection` or the new `RCC_CONNECTION`), if the line sets it.
 fn connection_key(line: &str) -> Option<&'static str> {
@@ -303,58 +311,6 @@ mod tests {
         );
     }
 
-    #[test]
-    fn toggle_after_line_records_diffs_for_toggled_section() {
-        let dir = TempProjectDir::new("toggle_section");
-        fs::write(
-            dir.join(LOCAL_CONNECTION_PATH),
-            "#docker\nDOCKER_HOST=tcp://localhost:2375\n#DOCKER_TLS_VERIFY=1\n#DOCKER_CERT_PATH=/certs\nDOCKER_API_VERSION=1.41\nother=1",
-        )
-        .unwrap();
-
-        let change = toggle_after_line("#docker", 4, true, &config_for(&dir)).unwrap();
-
-        assert_eq!(
-            change.diffs,
-            vec![
-                (
-                    "#DOCKER_TLS_VERIFY=1".to_string(),
-                    "DOCKER_TLS_VERIFY=1".to_string()
-                ),
-                (
-                    "#DOCKER_CERT_PATH=/certs".to_string(),
-                    "DOCKER_CERT_PATH=/certs".to_string()
-                ),
-            ]
-        );
-    }
-
-    #[test]
-    fn toggle_after_line_records_diffs_for_both_connection_keys() {
-        let dir = TempProjectDir::new("connection_keys");
-        fs::write(
-            dir.join(LOCAL_CONNECTION_PATH),
-            "#docker\nline1\nline2\nline3\nline4\nconnection='staging'\nRCC_CONNECTION='staging'",
-        )
-        .unwrap();
-
-        let change = toggle_after_line("#cidb", 2, false, &config_for(&dir)).unwrap();
-
-        assert_eq!(
-            change.diffs,
-            vec![
-                (
-                    "connection='staging'".to_string(),
-                    "connection='ci'".to_string()
-                ),
-                (
-                    "RCC_CONNECTION='staging'".to_string(),
-                    "RCC_CONNECTION='ci'".to_string()
-                ),
-            ]
-        );
-    }
-
     #[test]
     fn set_dot_env_merges_diffs_from_both_sections() {
         let dir = TempProjectDir::new("merge_sections");
@@ -386,6 +342,39 @@ mod tests {
         }
     }
 
+    #[test]
+    fn set_dot_env_merges_diffs_from_both_sections_on_stop() {
+        let dir = TempProjectDir::new("merge_sections_stop");
+        fs::write(
+            dir.join(LOCAL_CONNECTION_PATH),
+            "#docker\nDOCKER_HOST=tcp://localhost:2375\n#DOCKER_TLS_VERIFY=1\n#DOCKER_CERT_PATH=/certs\nDOCKER_API_VERSION=1.41\n#cidb\n#ci.db.master.ip=127.0.0.1\n#ci.db.master.port=5432\nconnection='ci'\nRCC_CONNECTION='ci'",
+        )
+        .unwrap();
+
+        let change = set_dot_env(false, &config_for(&dir)).unwrap();
+
+        assert_eq!(change.diffs.len(), 6);
+        for expected in [
+            (
+                "DOCKER_HOST=tcp://localhost:2375",
+                "#DOCKER_HOST=tcp://localhost:2375",
+            ),
+            ("DOCKER_API_VERSION=1.41", "#DOCKER_API_VERSION=1.41"),
+            ("#ci.db.master.ip=127.0.0.1", "ci.db.master.ip=127.0.0.1"),
+            ("#ci.db.master.port=5432", "ci.db.master.port=5432"),
+            ("connection='ci'", "connection='staging'"),
+            ("RCC_CONNECTION='ci'", "RCC_CONNECTION='staging'"),
+        ] {
+            assert!(
+                change
+                    .diffs
+                    .contains(&(expected.0.to_string(), expected.1.to_string())),
+                "missing diff {:?}",
+                expected
+            );
+        }
+    }
+
     #[test]
     fn file_change_display_no_diffs() {
         let change = FileChange {

src/main.rs

@@ -22,14 +22,9 @@ fn main() -> Result<()> {
     let start: bool = args.action == "up";
 
     start_docker_compose(&config.container_service, &config.container_dir, start)?;
-    if args.legacy {
+
-        println!("[!] Legacy mode active.");
     print!("{}", set_local_db(start, &config)?);
     toggle_index(start, &config)?;
-    } else {
-        println!("[!] Legacy mode deactivated.");
-    }
-
     print!("{}", set_dot_env(start, &config)?);
 
     println!(