Add snakefmt (#307)

https://github.com/snakemake/snakefmt

---------

Co-authored-by: Radon Rosborough <radon@intuitiveexplanations.com>

5 files changed, 74 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7709f62..9d0d67b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,8 @@ The format is based on [Keep a Changelog].
   [typst](https://typst.app/) ([#313]).
 * [`rubocop`](https://github.com/rubocop/rubocop) changed to use `-a`
   instead of deprecated `--auto-correct` ([#316]).
+* `snakefmt` official formatter for
+  [Snakemake](https://snakemake.readthedocs.io) ([#307]).
 
 ### Bugs fixed
 * `apheleia-npx` would use an incorrect path for the Yarn PnP ESM
@@ -38,6 +40,7 @@ The format is based on [Keep a Changelog].
 
 [#301]: https://github.com/radian-software/apheleia/pull/301
 [#306]: https://github.com/radian-software/apheleia/pull/306
+[#307]: https://github.com/radian-software/apheleia/pull/307
 [#309]: https://github.com/radian-software/apheleia/issues/309
 [#312]: https://github.com/radian-software/apheleia/issues/312
 [#313]: https://github.com/radian-software/apheleia/pull/313
diff --git a/apheleia-formatters.el b/apheleia-formatters.el
index 77e07ef..d1f3750 100644
--- a/apheleia-formatters.el
+++ b/apheleia-formatters.el
@@ -176,6 +176,9 @@
                    "--fix" "--fix-only"
                    "--stdin-filename" filepath
                    "-"))
+    (snakefmt . ("snakefmt"
+                 (apheleia-formatters-fill-column "--line-length")
+                 "-"))
     (shfmt . ("shfmt"
               "-filename" filepath
               "-ln" (cl-case (bound-and-true-p sh-shell)
@@ -356,6 +359,7 @@ rather than using this system."
     (rustic-mode . rustfmt)
     (rust-mode . rustfmt)
     (rust-ts-mode . rustfmt)
+    (snakemake-mode . snakefmt)
     (scss-mode . prettier-scss)
     (sql-mode . pgformatter)
     (svelte-mode . prettier-svelte)
diff --git a/test/formatters/installers/snakefmt.bash b/test/formatters/installers/snakefmt.bash
new file mode 100644
index 0000000..003234d
--- /dev/null
+++ b/test/formatters/installers/snakefmt.bash
@@ -0,0 +1,2 @@
+apt-get install -y python3-pip
+pip install snakefmt
diff --git a/test/formatters/samplecode/snakefmt/in.smk b/test/formatters/samplecode/snakefmt/in.smk
new file mode 100644
index 0000000..10adc3c
--- /dev/null
+++ b/test/formatters/samplecode/snakefmt/in.smk
@@ -0,0 +1,21 @@
+from snakemake.utils import min_version
+min_version("5.14.0")
+configfile: "config.yaml" # snakemake keywords are treated like classes i.e. 2 newlines
+SAMPLES = ['s1', 's2'] # strings are normalised
+CONDITIONS = ["a", "b", "longlonglonglonglonglonglonglonglonglonglonglonglonglonglonglong"] # long lines are wrapped
+include: "rules/foo.smk" # 2 newlines
+
+rule all:
+    input: "data/results.txt" # newlines after keywords enforced and trailing comma
+
+rule gets_separated_by_two_newlines:
+    input:
+        files = expand("long/string/to/data/files/gets_broken_by_black/{sample}.{condition}",sample=SAMPLES, condition=CONDITIONS)
+if True:
+    rule can_be_inside_python_code:
+        input: "parameters", "get_indented"
+        threads: 4 # Numeric params stay unindented
+        params: key_val = "PEP8_formatted"
+        run:
+
+                print("weirdly_spaced_string_gets_respaced")
diff --git a/test/formatters/samplecode/snakefmt/out.smk b/test/formatters/samplecode/snakefmt/out.smk
new file mode 100644
index 0000000..049f04c
--- /dev/null
+++ b/test/formatters/samplecode/snakefmt/out.smk
@@ -0,0 +1,44 @@
+from snakemake.utils import min_version
+
+min_version("5.14.0")
+
+
+configfile: "config.yaml"  # snakemake keywords are treated like classes i.e. 2 newlines
+
+
+SAMPLES = ["s1", "s2"]  # strings are normalised
+CONDITIONS = [
+    "a",
+    "b",
+    "longlonglonglonglonglonglonglonglonglonglonglonglonglonglonglong",
+]  # long lines are wrapped
+
+
+include: "rules/foo.smk"  # 2 newlines
+
+
+rule all:
+    input:
+        "data/results.txt",  # newlines after keywords enforced and trailing comma
+
+
+rule gets_separated_by_two_newlines:
+    input:
+        files=expand(
+            "long/string/to/data/files/gets_broken_by_black/{sample}.{condition}",
+            sample=SAMPLES,
+            condition=CONDITIONS,
+        ),
+
+
+if True:
+
+    rule can_be_inside_python_code:
+        input:
+            "parameters",
+            "get_indented",
+        threads: 4  # Numeric params stay unindented
+        params:
+            key_val="PEP8_formatted",
+        run:
+            print("weirdly_spaced_string_gets_respaced")