feature: Support --diff-context option to wolfram-cli paclet test

This commits code that was written many months ago.

Author: ConnorGray

WolframCLI/Source/WolframCLI/WolframCLI.wl

@@ -37,11 +37,23 @@ SetOptions[$Output, FormatType -> TerminalForm]
 
 (*====================================*)
 
+Options[CommandPacletTest] = {
+	(*
+		Maximum lines of context to include around textual diffs shown in
+		failed test results.
+	*)
+	"DiffContext" -> 10
+}
+
 (* Handle `$ wolfram paclet test` *)
 CommandPacletTest[
 	pacletDir: _?StringQ,
-	testsPath: _?StringQ | Automatic : Automatic
-] := Module[{
+	testsPath: _?StringQ | Automatic : Automatic,
+	OptionsPattern[]
+] := With[{
+	diffContext = RaiseConfirmMatch[OptionValue["DiffContext"], _?IntegerQ]
+},
+Module[{
 	result,
 	linkObj
 },
@@ -200,7 +212,7 @@ CommandPacletTest[
 
 		logger = Function[testResult,
 			summaryData[testResult["Outcome"]] += 1;
-			printTestResult[testResult];
+			printTestResult[testResult, diffContext];
 		];
 
 		logger = <|
@@ -303,19 +315,13 @@ CommandPacletTest[
 			)
 		}];
 	];
-]
+]]
 
 (*------------------------------------*)
 
-(*
-	Function with argument structure used by the
-	"Log(Success|Failure|MessagesFailure|Error)" events.
-*)
-testOutcomeLogger[test_TestResultObject] := printTestResult[test]
-
-(*------------------------------------*)
+SetFallthroughError[printTestResult]
 
-printTestResult[test_TestResultObject] := Module[{},
+printTestResult[test_TestResultObject, diffContext_?IntegerQ] := Module[{},
 	Replace[test["Outcome"], {
 		"Success" :> Print[Format[test, TerminalForm]],
 		"Failure" :> Module[{
@@ -341,7 +347,7 @@ printTestResult[test_TestResultObject] := Module[{},
 			a = Replace[test["ExpectedOutput"], HoldForm[x_] :> x];
 			b = Replace[test["ActualOutput"], HoldForm[x_] :> x];
 
-			printTextualExprDiff[a, b]
+			printTextualExprDiff[a, b, diffContext]
 		],
 		"Error" :> Module[{},
 			Print[Format[test, TerminalForm]];
@@ -389,7 +395,7 @@ printTestResult[test_TestResultObject] := Module[{},
 			a = Replace[test["ExpectedMessages"], HoldForm[x_] :> x];
 			b = Replace[test["ActualMessages"], HoldForm[x_] :> x];
 
-			printTextualExprDiff[a, b]
+			printTextualExprDiff[a, b, diffContext]
 		],
 		(* FIXME: Expand this to cover all outcomes *)
 		other_ :> (
@@ -399,9 +405,14 @@ printTestResult[test_TestResultObject] := Module[{},
 	}]
 ]
 
+(*------------------------------------*)
+
+SetFallthroughError[printTextualExprDiff]
+
 printTextualExprDiff[
 	expr1_,
-	expr2_
+	expr2_,
+	diffContext : _?IntegerQ : 10
 ] := (
 	Needs["CodeFormatter`" -> None];
 
@@ -417,17 +428,17 @@ printTextualExprDiff[
 
 		Scan[
 			Replace[{
-				common:{__?StringQ} :> (
+				common:{__?StringQ} :> Module[{context},
 					(* If the diff is large, elide everything but the first and
 					   last 10 lines. *)
-					If[Length[common] > 20,
-						Print["  ", StringRiffle[Take[common, 10], "\n"]]
-						Print[TerminalStyle["<<" <> ToString[Length[common] - 20] <> ">>", "Blue"]];
-						Print["  ", StringRiffle[Take[common, -10], "\n"]]
+					If[Length[common] > 2 * diffContext,
+						Print["  ", StringRiffle[Take[common, diffContext], "\n"]]
+						Print[TerminalStyle["<<" <> ToString[Length[common] - 2 * diffContext] <> ">>", "Blue"]];
+						Print["  ", StringRiffle[Take[common, -diffContext], "\n"]]
 						,
 						Print["  ", StringRiffle[common, "\n"]]
 					]
-				),
+				],
 				{expected:{___?StringQ}, got:{___?StringQ}} :> (
 					Print[TerminalStyle["- ", "Red"], TerminalStyle[StringRiffle[expected, "\n"], "Red"]];
 					Print[TerminalStyle["+ ", "Green"], TerminalStyle[StringRiffle[got, "\n"], "Green"]];

crates/wolfram-cli/src/main.rs

@@ -125,6 +125,10 @@ enum PacletCommand {
 
 		/// Optional file or directory containing tests to be run.
 		tests_path: Option<PathBuf>,
+
+		/// Lines of context to print before and after a diff in test output.
+		#[arg(long, short = 'C')]
+		diff_context: Option<usize>,
 	},
 }
 
@@ -214,7 +218,8 @@ fn handle_paclet_command(command: PacletCommand) {
 		PacletCommand::Test {
 			paclet_dir,
 			tests_path,
-		} => handle_paclet_test(paclet_dir, tests_path),
+			diff_context,
+		} => handle_paclet_test(paclet_dir, tests_path, diff_context),
 	}
 }
 
@@ -229,7 +234,8 @@ fn handle_wolfram() {
 	let mut line = String::new();
 
 	loop {
-		let Some(input_name) = process_until_ready_for_input(&mut kernel) else {
+		let Some(input_name) = process_until_ready_for_input(&mut kernel)
+		else {
 			break;
 		};
 
@@ -607,6 +613,7 @@ fn handle_paclet_doc(
 fn handle_paclet_test(
 	paclet_dir: Option<PathBuf>,
 	tests_path: Option<PathBuf>,
+	diff_context: Option<usize>,
 ) {
 	let paclet_dir = unwrap_path_or_default_to_current_dir(paclet_dir);
 	let paclet_dir: &str = match paclet_dir.to_str() {
@@ -625,13 +632,32 @@ fn handle_paclet_test(
 
 	let mut args = vec![Expr::string(paclet_dir)];
 
+	//
+	// Optional arguments
+	//
+
 	if let Some(tests_path) = tests_path {
 		let tests_path = tests_path
 			.to_str()
 			.expect("paclet tests path is not valid UTF-8");
 		args.push(Expr::string(tests_path));
 	}
 
+	//
+	// Options
+	//
+
+	if let Some(diff_context) = diff_context {
+		args.push(Expr::rule(
+			Expr::string("DiffContext"),
+			Expr::from(
+				i64::try_from(diff_context)
+					.expect("diff context overflows i64"),
+			),
+		));
+	}
+
+
 	// Evaluate:
 	//
 	//     CommandPacletTest[paclet_dir]

docs/CommandLineHelp.md

@@ -125,13 +125,17 @@ Run tests defined for a paclet
 
 This uses `` PacletTools`PacletTest `` to execute any tests defined by the specified paclet.
 
-**Usage:** `wolfram-cli paclet test [PACLET_DIR] [TESTS_PATH]`
+**Usage:** `wolfram-cli paclet test [OPTIONS] [PACLET_DIR] [TESTS_PATH]`
 
 ###### **Arguments:**
 
 * `<PACLET_DIR>` — Optional path to a paclet directory
 * `<TESTS_PATH>` — Optional file or directory containing tests to be run
 
+###### **Options:**
+
+* `-C`, `--diff-context <DIFF_CONTEXT>` — Lines of context to print before and after a diff in test output
+
 
 
 <hr/>

docs/Development.md

@@ -24,4 +24,10 @@ $ wolfram-cli paclet test ./build/ConnorGray__WolframCLI ./Tests
 
 ```
 $ wolfram print-terminal-form-debug
+```
+
+#### Regenerate docs/CommandLineHelp.md
+
+```
+$ cargo run -- print-all-help --markdown > docs/CommandLineHelp.md
 ```