Improvements for compare.character

[krlmlr]

• bugfix: don't show more items than necessary when comparing long vectors with few differences
• bugfix: reverse order in expectation so that output of detailed comparison matches expectation output
• compare vectors of different length in detail
  • if one vector is shorter, hide (non-existing) value in detailed diff

Similar improvements for compare.numeric are possible but not yet implemented.

Examples:

> expect_equal(letters, c(letters[-26], "a"))
Error: letters not equal to c(letters[-26], "a")
1 string mismatches:
x[26]: "z"
y[26]: "a"
> expect_equal(letters, c("A", letters[-c(1,25,26)]))
Error: letters not equal to c("A", letters[-c(1, 25, 26)])
Lengths (26, 24) differ
3 string mismatches:
x[1]: "a"
y[1]: "A"

x[25]: "y"

x[26]: "z"

Current state:

> expect_equal(letters, c(letters[-26], "a"))
Error: letters not equal to c(letters[-26], "a")
1 string mismatches:
x[26]: "a"
y[26]: "z"

x[NA]: NA
y[NA]: NA

x[NA]: NA
y[NA]: NA

x[NA]: NA
y[NA]: NA

x[NA]: NA
y[NA]: NA
> expect_equal(letters, c("A", letters[-c(1,25,26)]))
Error: letters not equal to c("A", letters[-c(1, 25, 26)])
Lengths (24, 26) differ (string compare on first 24)
1 string mismatch

[hadley]

Should be <- not =

[hadley]

Looks good - just a few minor suggestions.

[krlmlr]

Done. Tests succeed, but covr seems to be hanging for the PR test...

[hadley]

Thanks!