From bfd06fa0967b441c5aecfcb992500b9ee240a267 Mon Sep 17 00:00:00 2001 From: Alana Gilston Date: Sat, 19 Apr 2025 08:26:51 -0700 Subject: [PATCH] Add -B, -A, and -C options to grep (#1206) Adds the -B (before context), -A (after context), and -C (before+after context) options to grep. Example usage: ``` grep -B [args...] grep -A [args...] ``` --- README.md | 6 + src/grep.js | 126 +++++++++++++++++++- test/grep.js | 240 ++++++++++++++++++++++++++++++++++++++ test/resources/grep/file3 | 15 +++ 4 files changed, 381 insertions(+), 6 deletions(-) create mode 100644 test/resources/grep/file3 diff --git a/README.md b/README.md index e585e4b..a0de676 100644 --- a/README.md +++ b/README.md @@ -419,12 +419,18 @@ Available options: + `-l`: Print only filenames of matching files. + `-i`: Ignore case. + `-n`: Print line numbers. ++ `-B `: Show `` lines before each result. ++ `-A `: Show `` lines after each result. ++ `-C `: Show `` lines before and after each result. -B and -A override this option. Examples: ```javascript grep('-v', 'GLOBAL_VARIABLE', '*.js'); grep('GLOBAL_VARIABLE', '*.js'); +grep('-B', 3, 'GLOBAL_VARIABLE', '*.js'); +grep({ '-B': 3 }, 'GLOBAL_VARIABLE', '*.js'); +grep({ '-B': 3, '-C': 2 }, 'GLOBAL_VARIABLE', '*.js'); ``` Reads input string from given files and returns a diff --git a/src/grep.js b/src/grep.js index 63792e6..cfc83e4 100644 --- a/src/grep.js +++ b/src/grep.js @@ -9,6 +9,9 @@ common.register('grep', _grep, { 'l': 'nameOnly', 'i': 'ignoreCase', 'n': 'lineNumber', + 'B': 'beforeContext', + 'A': 'afterContext', + 'C': 'context', }, }); @@ -22,12 +25,18 @@ common.register('grep', _grep, { //@ + `-l`: Print only filenames of matching files. //@ + `-i`: Ignore case. //@ + `-n`: Print line numbers. +//@ + `-B `: Show `` lines before each result. +//@ + `-A `: Show `` lines after each result. +//@ + `-C `: Show `` lines before and after each result. -B and -A override this option. //@ //@ Examples: //@ //@ ```javascript //@ grep('-v', 'GLOBAL_VARIABLE', '*.js'); //@ grep('GLOBAL_VARIABLE', '*.js'); +//@ grep('-B', 3, 'GLOBAL_VARIABLE', '*.js'); +//@ grep({ '-B': 3 }, 'GLOBAL_VARIABLE', '*.js'); +//@ grep({ '-B': 3, '-C': 2 }, 'GLOBAL_VARIABLE', '*.js'); //@ ``` //@ //@ Reads input string from given files and returns a @@ -39,7 +48,41 @@ function _grep(options, regex, files) { if (!files && !pipe) common.error('no paths given', 2); - files = [].slice.call(arguments, 2); + var idx = 2; + var contextError = ': invalid context length argument'; + // If the option has been found but not read, copy value from arguments + if (options.beforeContext === true) { + idx = 3; + options.beforeContext = Number(arguments[1]); + if (options.beforeContext < 0) { + common.error(options.beforeContext + contextError, 2); + } + } + if (options.afterContext === true) { + idx = 3; + options.afterContext = Number(arguments[1]); + if (options.afterContext < 0) { + common.error(options.afterContext + contextError, 2); + } + } + if (options.context === true) { + idx = 3; + options.context = Number(arguments[1]); + if (options.context < 0) { + common.error(options.context + contextError, 2); + } + } + // If before or after not given but context is, update values + if (typeof options.context === 'number') { + if (options.beforeContext === false) { + options.beforeContext = options.context; + } + if (options.afterContext === false) { + options.afterContext = options.context; + } + } + regex = arguments[idx - 1]; + files = [].slice.call(arguments, idx); if (pipe) { files.unshift('-'); @@ -62,16 +105,79 @@ function _grep(options, regex, files) { } } else { var lines = contents.split('\n'); + var matches = []; + lines.forEach(function (line, index) { var matched = line.match(regex); if ((options.inverse && !matched) || (!options.inverse && matched)) { - var result = line; - if (options.lineNumber) { - result = '' + (index + 1) + ':' + line; + var lineNumber = index + 1; + var result = {}; + if (matches.length > 0) { + // If the last result intersects, combine them + var last = matches[matches.length - 1]; + var minimumLineNumber = Math.max( + 1, + lineNumber - options.beforeContext - 1, + ); + if ( + last.hasOwnProperty('' + lineNumber) || + last.hasOwnProperty('' + minimumLineNumber) + ) { + result = last; + } + } + result[lineNumber] = { + line, + match: true, + }; + if (options.beforeContext > 0) { + // Store the lines with their line numbers to check for overlap + lines + .slice(Math.max(index - options.beforeContext, 0), index) + .forEach(function (v, i, a) { + var lineNum = '' + (index - a.length + i + 1); + if (!result.hasOwnProperty(lineNum)) { + result[lineNum] = { line: v, match: false }; + } + }); + } + if (options.afterContext > 0) { + // Store the lines with their line numbers to check for overlap + lines + .slice( + index + 1, + Math.min(index + options.afterContext + 1, lines.length - 1), + ) + .forEach(function (v, i) { + var lineNum = '' + (index + 1 + i + 1); + if (!result.hasOwnProperty(lineNum)) { + result[lineNum] = { line: v, match: false }; + } + }); + } + // Only add the result if it's new + if (!matches.includes(result)) { + matches.push(result); } - grep.push(result); } }); + + // Loop through the matches and add them to the output + Array.prototype.push.apply( + grep, + matches.map(function (result) { + return Object.entries(result) + .map(function (entry) { + var lineNumber = entry[0]; + var line = entry[1].line; + var match = entry[1].match; + return options.lineNumber + ? lineNumber + (match ? ':' : '-') + line + : line; + }) + .join('\n'); + }), + ); } }); @@ -79,6 +185,14 @@ function _grep(options, regex, files) { // We didn't hit the error above, but pattern didn't match common.error('', { silent: true }); } - return grep.join('\n') + '\n'; + + var separator = '\n'; + if ( + typeof options.beforeContext === 'number' || + typeof options.afterContext === 'number' + ) { + separator = '\n--\n'; + } + return grep.join(separator) + '\n'; } module.exports = _grep; diff --git a/test/grep.js b/test/grep.js index e12ab80..4b64d6e 100644 --- a/test/grep.js +++ b/test/grep.js @@ -57,6 +57,27 @@ test("multiple files, one doesn't exist, one doesn't match", t => { t.is(result.code, 2); }); +test('-A option, negative value', t => { + const result = shell.grep('-A', -2, 'test*', 'test/resources/grep/file3'); + t.truthy(shell.error()); + t.is(result.code, 2); + t.is(result.stderr, 'grep: -2: invalid context length argument'); +}); + +test('-B option, negative value', t => { + const result = shell.grep('-B', -3, 'test*', 'test/resources/grep/file3'); + t.truthy(shell.error()); + t.is(result.code, 2); + t.is(result.stderr, 'grep: -3: invalid context length argument'); +}); + +test('-C option, negative value', t => { + const result = shell.grep('-C', -1, 'test*', 'test/resources/grep/file3'); + t.truthy(shell.error()); + t.is(result.code, 2); + t.is(result.stderr, 'grep: -1: invalid context length argument'); +}); + // // Valids // @@ -174,3 +195,222 @@ test('the pattern looks like an option', t => { t.falsy(shell.error()); t.is(result.toString(), '-v\n-vv\n'); }); + +// +// Before & after contexts +// +test('-B option', t => { + const result = shell.grep('-B', 3, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + 'line1\n' + + 'line2 test line\n' + + 'line3 test line\n' + + '--\n' + + 'line7\n' + + 'line8\n' + + 'line9\n' + + 'line10 test line\n' + + '--\n' + + 'line12\n' + + 'line13\n' + + 'line14\n' + + 'line15 test line\n', + ); +}); + +test('-B option, -n option', t => { + const result = shell.grep('-nB', 3, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + '1-line1\n' + + '2:line2 test line\n' + + '3:line3 test line\n' + + '--\n' + + '7-line7\n' + + '8-line8\n' + + '9-line9\n' + + '10:line10 test line\n' + + '--\n' + + '12-line12\n' + + '13-line13\n' + + '14-line14\n' + + '15:line15 test line\n', + ); +}); + +test('-A option', t => { + const result = shell.grep('-A', 2, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + 'line2 test line\n' + + 'line3 test line\n' + + 'line4\n' + + 'line5\n' + + '--\n' + + 'line10 test line\n' + + 'line11\n' + + 'line12\n' + + '--\n' + + 'line15 test line\n', + ); +}); + +test('-A option, -B option', t => { + const result = shell.grep( + { '-A': 2, '-B': 3 }, + 'test*', + 'test/resources/grep/file3', + ); + t.falsy(shell.error()); + t.is( + result.toString(), + 'line1\n' + + 'line2 test line\n' + + 'line3 test line\n' + + 'line4\n' + + 'line5\n' + + '--\n' + + 'line7\n' + + 'line8\n' + + 'line9\n' + + 'line10 test line\n' + + 'line11\n' + + 'line12\n' + + 'line13\n' + + 'line14\n' + + 'line15 test line\n', + ); +}); + +test('-A option, -B option, -n option', t => { + const result = shell.grep( + { '-n': true, '-A': 2, '-B': 3 }, + 'test*', + 'test/resources/grep/file3', + ); + t.falsy(shell.error()); + t.is( + result.toString(), + '1-line1\n' + + '2:line2 test line\n' + + '3:line3 test line\n' + + '4-line4\n' + + '5-line5\n' + + '--\n' + + '7-line7\n' + + '8-line8\n' + + '9-line9\n' + + '10:line10 test line\n' + + '11-line11\n' + + '12-line12\n' + + '13-line13\n' + + '14-line14\n' + + '15:line15 test line\n', + ); +}); + +test('-C option', t => { + const result = shell.grep('-C', 3, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + 'line1\n' + + 'line2 test line\n' + + 'line3 test line\n' + + 'line4\n' + + 'line5\n' + + 'line6\n' + + 'line7\n' + + 'line8\n' + + 'line9\n' + + 'line10 test line\n' + + 'line11\n' + + 'line12\n' + + 'line13\n' + + 'line14\n' + + 'line15 test line\n', + ); +}); + +test('-C option, small value', t => { + const result = shell.grep('-C', 1, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + 'line1\n' + + 'line2 test line\n' + + 'line3 test line\n' + + 'line4\n' + + '--\n' + + 'line9\n' + + 'line10 test line\n' + + 'line11\n' + + '--\n' + + 'line14\n' + + 'line15 test line\n', + ); +}); + +test('-C option, large value', t => { + const result = shell.grep('-C', 100, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + 'line1\n' + + 'line2 test line\n' + + 'line3 test line\n' + + 'line4\n' + + 'line5\n' + + 'line6\n' + + 'line7\n' + + 'line8\n' + + 'line9\n' + + 'line10 test line\n' + + 'line11\n' + + 'line12\n' + + 'line13\n' + + 'line14\n' + + 'line15 test line\n', + ); +}); + +test('-C option, add line separators', t => { + const result = shell.grep('-C', 0, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + 'line2 test line\n' + + 'line3 test line\n' + + '--\n' + + 'line10 test line\n' + + '--\n' + + 'line15 test line\n', + ); +}); + +test('-C option, -n option', t => { + const result = shell.grep('-nC', 3, 'test*', 'test/resources/grep/file3'); + t.falsy(shell.error()); + t.is( + result.toString(), + '1-line1\n' + + '2:line2 test line\n' + + '3:line3 test line\n' + + '4-line4\n' + + '5-line5\n' + + '6-line6\n' + + '7-line7\n' + + '8-line8\n' + + '9-line9\n' + + '10:line10 test line\n' + + '11-line11\n' + + '12-line12\n' + + '13-line13\n' + + '14-line14\n' + + '15:line15 test line\n', + ); +}); diff --git a/test/resources/grep/file3 b/test/resources/grep/file3 new file mode 100644 index 0000000..e4bee9f --- /dev/null +++ b/test/resources/grep/file3 @@ -0,0 +1,15 @@ +line1 +line2 test line +line3 test line +line4 +line5 +line6 +line7 +line8 +line9 +line10 test line +line11 +line12 +line13 +line14 +line15 test line