feat(fossil_metrics): add fossil_metrics module (#4874)

* feat(fossil_metrics): add fossil_metrics module

* Return early if not in a Fossil check-out

* Add more tests for fossil_metrics

* Move is in Fossil checkout check after module enabled check

* Update type for new toml version

* Update the config file schema

* Rework parsing of fossil diff output

* Fix Fossil check-out detection in subdirectories

* Use regex to only match expected fossil diff output

* Use shared ancestor scanning and fix detection on Windows

* Add note on minimum Fossil version

.github/config-schema.json

@@ -520,6 +520,20 @@
         }
       ]
     },
+    "fossil_metrics": {
+      "default": {
+        "added_style": "bold green",
+        "deleted_style": "bold red",
+        "disabled": true,
+        "format": "([+$added]($added_style) )([-$deleted]($deleted_style) )",
+        "only_nonzero_diffs": true
+      },
+      "allOf": [
+        {
+          "$ref": "#/definitions/FossilMetricsConfig"
+        }
+      ]
+    },
     "gcloud": {
       "default": {
         "detect_env_vars": [],
@@ -3068,6 +3082,32 @@
       },
       "additionalProperties": false
     },
+    "FossilMetricsConfig": {
+      "type": "object",
+      "properties": {
+        "format": {
+          "default": "([+$added]($added_style) )([-$deleted]($deleted_style) )",
+          "type": "string"
+        },
+        "added_style": {
+          "default": "bold green",
+          "type": "string"
+        },
+        "deleted_style": {
+          "default": "bold red",
+          "type": "string"
+        },
+        "only_nonzero_diffs": {
+          "default": true,
+          "type": "boolean"
+        },
+        "disabled": {
+          "default": true,
+          "type": "boolean"
+        }
+      },
+      "additionalProperties": false
+    },
     "GcloudConfig": {
       "type": "object",
       "properties": {

docs/config/README.md

@@ -266,6 +266,7 @@ $kubernetes\
 $directory\
 $vcsh\
 $fossil_branch\
+$fossil_metrics\
 $git_branch\
 $git_commit\
 $git_state\
@@ -1604,6 +1605,41 @@ truncation_length = 4
 truncation_symbol = ''
 ```
 
+## Fossil Metrics
+
+The `fossil_metrics` module will show the number of added and deleted lines in the check-out in your current directory. At least v2.14 (2021-01-20) of Fossil is required.
+
+### Options
+
+| Option               | Default                                                      | Description                           |
+| -------------------- | ------------------------------------------------------------ | ------------------------------------- |
+| `format`             | `'([+$added]($added_style) )([-$deleted]($deleted_style) )'` | The format for the module.            |
+| `added_style`        | `'bold green'`                                               | The style for the added count.        |
+| `deleted_style`      | `'bold red'`                                                 | The style for the deleted count.      |
+| `only_nonzero_diffs` | `true`                                                       | Render status only for changed items. |
+| `disabled`           | `true`                                                       | Disables the `fossil_metrics` module. |
+
+### Variables
+
+| Variable        | Example | Description                                 |
+| --------------- | ------- | ------------------------------------------- |
+| added           | `1`     | The current number of added lines           |
+| deleted         | `2`     | The current number of deleted lines         |
+| added_style\*   |         | Mirrors the value of option `added_style`   |
+| deleted_style\* |         | Mirrors the value of option `deleted_style` |
+
+*: This variable can only be used as a part of a style string
+
+### Example
+
+```toml
+# ~/.config/starship.toml
+
+[fossil_metrics]
+added_style = 'bold blue'
+format = '[+$added]($added_style)/[-$deleted]($deleted_style) '
+```
+
 ## Google Cloud (`gcloud`)
 
 The `gcloud` module shows the current configuration for [`gcloud`](https://cloud.google.com/sdk/gcloud) CLI.

src/configs/fossil_metrics.rs

@@ -0,0 +1,28 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Deserialize, Serialize)]
+#[cfg_attr(
+    feature = "config-schema",
+    derive(schemars::JsonSchema),
+    schemars(deny_unknown_fields)
+)]
+#[serde(default)]
+pub struct FossilMetricsConfig<'a> {
+    pub format: &'a str,
+    pub added_style: &'a str,
+    pub deleted_style: &'a str,
+    pub only_nonzero_diffs: bool,
+    pub disabled: bool,
+}
+
+impl<'a> Default for FossilMetricsConfig<'a> {
+    fn default() -> Self {
+        FossilMetricsConfig {
+            format: "([+$added]($added_style) )([-$deleted]($deleted_style) )",
+            added_style: "bold green",
+            deleted_style: "bold red",
+            only_nonzero_diffs: true,
+            disabled: true,
+        }
+    }
+}

src/configs/mod.rs

@@ -28,6 +28,7 @@ pub mod erlang;
 pub mod fennel;
 pub mod fill;
 pub mod fossil_branch;
+pub mod fossil_metrics;
 pub mod gcloud;
 pub mod git_branch;
 pub mod git_commit;
@@ -159,6 +160,8 @@ pub struct FullConfig<'a> {
     #[serde(borrow)]
     fossil_branch: fossil_branch::FossilBranchConfig<'a>,
     #[serde(borrow)]
+    fossil_metrics: fossil_metrics::FossilMetricsConfig<'a>,
+    #[serde(borrow)]
     gcloud: gcloud::GcloudConfig<'a>,
     #[serde(borrow)]
     git_branch: git_branch::GitBranchConfig<'a>,

src/configs/starship_root.rs

@@ -39,6 +39,7 @@ pub const PROMPT_ORDER: &[&str] = &[
     "directory",
     "vcsh",
     "fossil_branch",
+    "fossil_metrics",
     "git_branch",
     "git_commit",
     "git_state",

src/module.rs

@@ -35,6 +35,7 @@ pub const ALL_MODULES: &[&str] = &[
     "fennel",
     "fill",
     "fossil_branch",
+    "fossil_metrics",
     "gcloud",
     "git_branch",
     "git_commit",