better error handling with unit tests!

ERRORS.md

@@ -0,0 +1,15 @@
+#Error Handling
+Below you can find a more detailed explanation of some of the errors that can be encountered while using ftcsv. For parsing, examples of these files can be found in /spec/bad_csvs/
+
+
+
+##Parsing
+Note: `[row_number]` indicates the row number of the parsed lua table. As such, it will be one off from the line number in the csv. However, for header-less files, the row returned *will* match the csv line number.
+
+| Error Message  | Detailed Explanation |
+| ------------- | ------------- |
+| ftcsv: Cannot parse an empty file         | The file passed in contains no information. It is an empty file. |
+| ftcsv: Cannot parse a file which contains empty headers | If a header field contains no information, then it can't be parsed <br> (ex: `Name,City,,Zipcode`) |
+| ftcsv: too few columns in row [row_number]    | The number of columns is less than the amount in the header after transformations (renaming, keeping certain fields, etc) |
+| ftcsv: too many columns in row [row_number]   | The number of columns is greater than the amount in the header after transformations. It can't map the field's count with an existing header. |
+| ftcsv: File not found at [path]           | When loading, lua can't open the file at [path] | 

README.md

@@ -117,8 +117,14 @@ I did some basic testing and found that in lua, if you want to iterate over a st
 
 
 
+## Error Handling
+ftcsv returns a litany of errors when passed a bad csv file or incorrect parameters. You can find a more detailed explanation of the more cryptic errors in [ERRORS.md](ERRORS.md)
+
+
+
 ## Contributing
 Feel free to create a new issue for any bugs you've found or help you need. If you want to contribute back to the project please do the following:
+ 0. If it's a major change (aka more than a quick little < 5 line bugfix), please create an issue so we can discuss it!
  1. Fork the repo
  2. Create a new branch
  3. Push your changes to the branch

ftcsv-1.1.2-1.rockspec

@@ -1,9 +1,9 @@
 package = "ftcsv"
-version = "1.1.1-1"
+version = "1.1.2-1"
 
 source = {
 	url = "git://github.com/FourierTransformer/ftcsv.git",
-	tag = "1.1.1"
+	tag = "1.1.2"
 }
 
 description = {

ftcsv.lua

@@ -1,5 +1,5 @@
 local ftcsv = {
-    _VERSION = 'ftcsv 1.1.1',
+    _VERSION = 'ftcsv 1.1.2',
     _DESCRIPTION = 'CSV library for Lua',
     _URL         = 'https://github.com/FourierTransformer/ftcsv',
     _LICENSE     = [[
@@ -97,7 +97,7 @@ end
 -- load an entire file into memory
 local function loadFile(textFile)
     local file = io.open(textFile, "r")
-    if not file then error("File not found at " .. textFile) end
+    if not file then error("ftcsv: File not found at " .. textFile) end
     local allLines = file:read("*all")
     file:close()
     return allLines
@@ -156,7 +156,21 @@ local function parseString(inputString, inputLength, delimiter, i, headerField,
         outResults = {}
         outResults[1] = {}
         assignValue = function()
-            outResults[lineNum][headerField[fieldNum]] = field
+            if not pcall(function()
+                outResults[lineNum][headerField[fieldNum]] = field
+            end) then
+                error('ftcsv: too many columns in row ' .. lineNum)
+            end
+        end
+    end
+
+    -- calculate the initial line count (note: this can include duplicates)
+    local headerFieldsExist = {}
+    local initialLineCount = 0
+    for _, value in pairs(headerField) do
+        if not headerFieldsExist[value] and (fieldsToKeep == nil or fieldsToKeep[value]) then
+            headerFieldsExist[value] = true
+            initialLineCount = initialLineCount + 1
         end
     end
 
@@ -225,6 +239,9 @@ local function parseString(inputString, inputLength, delimiter, i, headerField,
             end
 
             -- incrememnt for new line
+            if fieldNum < initialLineCount then
+                error('ftcsv: too few columns in row ' .. lineNum)
+            end
             lineNum = lineNum + 1
             outResults[lineNum] = {}
             fieldNum = 1
@@ -251,16 +268,20 @@ local function parseString(inputString, inputLength, delimiter, i, headerField,
     -- clean up last line if it's weird (this happens when there is a CRLF newline at end of file)
     -- doing a count gets it to pick up the oddballs
     local finalLineCount = 0
-    for _, _ in pairs(outResults[lineNum]) do
+    local lastValue = nil
+    for k, v in pairs(outResults[lineNum]) do
         finalLineCount = finalLineCount + 1
+        lastValue = v
     end
-    local initialLineCount = 0
+
-    for _, _ in pairs(outResults[1]) do
+    -- this indicates a CRLF
-        initialLineCount = initialLineCount + 1
-    end
     -- print("Final/Initial", finalLineCount, initialLineCount)
-    if finalLineCount ~= initialLineCount then
+    if finalLineCount == 1 and lastValue == "" then
         outResults[lineNum] = nil
+
+    -- otherwise there might not be enough line
+    elseif finalLineCount < initialLineCount then
+        error('ftcsv: too few columns in row ' .. lineNum)
     end
 
     return outResults
@@ -295,8 +316,8 @@ function ftcsv.parse(inputFile, delimiter, options)
                     fieldsToKeep[ofieldsToKeep[j]] = true
                 end
             end
-            if header == false then
+            if header == false and options.rename == nil then
-                assert(next(rename) ~= nil, "ftcsv can only have fieldsToKeep for header-less files when they have been renamed. Please add the 'rename' option and try again.")
+                error("ftcsv: fieldsToKeep only works with header-less files when using the 'rename' functionality")
             end
         end
         if options.loadFromString ~= nil then
@@ -318,10 +339,22 @@ function ftcsv.parse(inputFile, delimiter, options)
     end
     local inputLength = #inputString
 
+    -- if they sent in an empty file...
+    if inputLength == 0 then
+        error('ftcsv: Cannot parse an empty file')
+    end
+
     -- parse through the headers!
     local headerField, i = parseString(inputString, inputLength, delimiter, 0)
     i = i + 1 -- start at the next char
 
+    -- make sure a header isn't empty
+    for _, header in ipairs(headerField) do
+        if #header == 0 then
+            error('ftcsv: Cannot parse a file which contains empty headers')
+        end
+    end
+
     -- for files where there aren't headers!
     if header == false then
         i = 0
@@ -347,7 +380,7 @@ function ftcsv.parse(inputFile, delimiter, options)
         end
     end
 
-    -- apply some sweet header manuipulation
+    -- apply some sweet header manipulation
     if headerFunc then
         for j = 1, #headerField do
             headerField[j] = headerFunc(headerField[j])
@@ -374,7 +407,7 @@ local function writer(inputTable, dilimeter, headers)
     -- they came in
     for i = 1, #headers do
         if inputTable[1][headers[i]] == nil then
-            error("the field '" .. headers[i] .. "' doesn't exist in the table")
+            error("ftcsv: the field '" .. headers[i] .. "' doesn't exist in the inputTable")
         end
         if headers[i]:find('"') then
             headers[i] = headers[i]:gsub('"', '\\"')

spec/bad_csvs/empty_file_newline.csv

@@ -0,0 +1 @@
+

spec/bad_csvs/empty_header.csv

@@ -0,0 +1,2 @@
+a,b,
+herp,derp

spec/bad_csvs/too_few_cols.csv

@@ -0,0 +1,3 @@
+a,b,c
+failing,hard
+man,oh,well...

spec/bad_csvs/too_few_cols_end.csv

@@ -0,0 +1,3 @@
+a,b,c
+man,oh,well...
+failing,hard

spec/bad_csvs/too_many_cols.csv

@@ -0,0 +1,3 @@
+a,b,c
+no,one,knows
+what,am,i,doing?

spec/error_spec.lua

@@ -0,0 +1,44 @@
+local ftcsv = require('ftcsv')
+
+local files = {
+	{"empty_file", "ftcsv: Cannot parse an empty file"},
+	{"empty_file_newline", "ftcsv: Cannot parse a file which contains empty headers"},
+	{"empty_header", "ftcsv: Cannot parse a file which contains empty headers"},
+	{"too_few_cols", "ftcsv: too few columns in row 1"},
+	{"too_few_cols_end", "ftcsv: too few columns in row 2"},
+	{"too_many_cols", "ftcsv: too many columns in row 2"},
+	{"dne", "ftcsv: File not found at spec/bad_csvs/dne.csv"}
+}
+
+describe("csv decode error", function()
+	for _, value in ipairs(files) do
+		it("should error out " .. value[1], function()
+			local test = function()
+				ftcsv.parse("spec/bad_csvs/" .. value[1] .. ".csv", ",")
+			end
+			assert.has_error(test, value[2])
+		end)
+	end
+end)
+
+it("should error out for fieldsToKeep if no headers and no renaming takes place", function()
+	local test = function()
+		local options = {loadFromString=true, headers=false, fieldsToKeep={1, 2}}
+		ftcsv.parse("apple>banana>carrot\ndiamond>emerald>pearl", ">", options)
+	end
+	assert.has_error(test, "ftcsv: fieldsToKeep only works with header-less files when using the 'rename' functionality")
+end)
+
+it("should error out when you want to encode a table and specify a field that doesn't exist", function()
+	local encodeThis = {
+	    {a = 'herp1', b = 'derp1'},
+	    {a = 'herp2', b = 'derp2'},
+	    {a = 'herp3', b = 'derp3'},
+	}
+
+	local test = function()
+		ftcsv.encode(encodeThis, ">", {fieldsToKeep={"c"}})
+	end
+
+	assert.has_error(test, "ftcsv: the field 'c' doesn't exist in the inputTable")
+end)

spec/feature_spec.lua

@@ -107,11 +107,6 @@ describe("csv features", function()
 		assert.are.same(expected, actual)
 	end)
 
-	it("should error out for fieldsToKeep if no headers and no renaming", function()
-		local options = {loadFromString=true, headers=false, fieldsToKeep={1, 2}}
-		assert.has.errors(function() ftcsv.parse("apple>banana>carrot\ndiamond>emerald>pearl", ">", options) end)
-	end)
-
 	it("should handle only renaming fields from files without headers", function()
 		local expected = {}
 		expected[1] = {}