Address review comments

Author: capnrefsmmat

R-packages/covidcast/R/covidcast.R

@@ -725,16 +725,18 @@ covidcast <- function(data_source, signal, time_type, geo_type, time_values,
     params$lag <- lag
   }
 
-  # Make the API call
-  res <- .request(params)
-  if (nchar(res) == 0) {
+  # Make the API call. If the API returns a non-200 status code, indicating e.g.
+  # a database error, .request() raises an error. It returns an empty string if
+  # there are no results for our query.
+  response <- .request(params)
+  if (nchar(response) == 0) {
     # empty if no results
     return(NULL)
   }
 
   # geo_value must be read as character so FIPS codes are returned as character,
   # not numbers (with leading 0s potentially removed)
-  return(read.csv(textConnection(res), stringsAsFactors = FALSE,
+  return(read.csv(textConnection(response), stringsAsFactors = FALSE,
                   colClasses = c("geo_value" = "character")))
 }
 

R-packages/covidcast/tests/testthat/api.covidcast.cmu.edu/epidata/api.php-32641f.csv

@@ -1,3 +1,3 @@
 geo_value,signal,time_value,direction,issue,lag,value,stderr,sample_size
 01001,bar,20200110,,20200111,1,91.2,0.8,114.2
-01002,bar,20200110,,20200111,1,99.1,0.2,217.8
+01002,bar,20200110,,20200111,1,99.1,0.2,217.8

R-packages/covidcast/tests/testthat/api.covidcast.cmu.edu/epidata/api.php-f49e8f.csv

@@ -1,3 +1,3 @@
 geo_value,signal,time_value,direction,issue,lag,value,stderr,sample_size
 31001,bar,20200112,,20200113,1,81.2,0.8,314.2
-31002,bar,20200112,,20200113,1,89.1,0.2,417.8
+31002,bar,20200112,,20200113,1,89.1,0.2,417.8

R-packages/covidcast/tests/testthat/test-covidcast.R

@@ -167,7 +167,7 @@ with_mock_api({
   })
 
   test_that("covidcast_signal stops when end_day < start_day", {
-    # reusing api.php-d2e163.json for metadata
+    # reusing api.php-dd024f.csv for metadata
     expect_error(covidcast_signal("foo", "bar", "2020-01-02", "2020-01-01"))
   })