float-values: Fix bug on strings containing fordidden values

The rule correctly reports number values like `.1`, `1e2`, `.NaN` and
`.Inf`, but it also reported false positives on strings like `.1two3`,
`1e2a`, `.NaNa` and `.Infinit∞`.

The regexps need to end with an end delimiter (`$`) otherwise longer
strings can be matched too.

Fixes https://github.com/adrienverge/yamllint/issues/495

tests/rules/test_float_values.py

@@ -40,6 +40,8 @@ class FloatValuesTestCase(RuleTestCase):
                    '- 0.0\n'
                    '- .1\n'
                    '- \'.1\'\n'
+                   '- string.1\n'
+                   '- .1string\n'
                    '- !custom_tag .2\n'
                    '- &angle1 0.0\n'
                    '- *angle1\n'
@@ -47,7 +49,7 @@ class FloatValuesTestCase(RuleTestCase):
                    '- *angle2\n',
                    conf,
                    problem1=(3, 3),
-                   problem2=(8, 11))
+                   problem2=(10, 11))
 
     def test_scientific_notation(self):
         conf = (
@@ -61,6 +63,8 @@ class FloatValuesTestCase(RuleTestCase):
                    '- 10e-6\n'
                    '- 0.00001\n'
                    '- \'10e-6\'\n'
+                   '- string10e-6\n'
+                   '- 10e-6string\n'
                    '- !custom_tag 10e-6\n'
                    '- &angle1 0.000001\n'
                    '- *angle1\n'
@@ -71,8 +75,8 @@ class FloatValuesTestCase(RuleTestCase):
                    conf,
                    problem1=(2, 3),
                    problem2=(3, 3),
-                   problem3=(9, 11),
-                   problem4=(11, 11))
+                   problem3=(11, 11),
+                   problem4=(13, 11))
 
     def test_nan(self):
         conf = (
@@ -85,13 +89,15 @@ class FloatValuesTestCase(RuleTestCase):
                    '- .NaN\n'
                    '- .NAN\n'
                    '- \'.NaN\'\n'
+                   '- a.NaN\n'
+                   '- .NaNa\n'
                    '- !custom_tag .NaN\n'
                    '- &angle .nan\n'
                    '- *angle\n',
                    conf,
                    problem1=(2, 3),
                    problem2=(3, 3),
-                   problem3=(6, 10))
+                   problem3=(8, 10))
 
     def test_inf(self):
         conf = (
@@ -106,6 +112,8 @@ class FloatValuesTestCase(RuleTestCase):
                    '- -.inf\n'
                    '- -.INF\n'
                    '- \'.inf\'\n'
+                   '- ∞.infinity\n'
+                   '- .infinity∞\n'
                    '- !custom_tag .inf\n'
                    '- &angle .inf\n'
                    '- *angle\n'
@@ -116,5 +124,5 @@ class FloatValuesTestCase(RuleTestCase):
                    problem2=(3, 3),
                    problem3=(4, 3),
                    problem4=(5, 3),
-                   problem5=(8, 10),
-                   problem6=(10, 10))
+                   problem5=(10, 10),
+                   problem6=(12, 10))

yamllint/rules/float_values.py

@@ -107,13 +107,13 @@ DEFAULT = {
 }
 
 IS_NUMERAL_BEFORE_DECIMAL_PATTERN = (
-    re.compile('[-+]?(\\.[0-9]+)([eE][-+]?[0-9]+)?')
+    re.compile('[-+]?(\\.[0-9]+)([eE][-+]?[0-9]+)?$')
 )
 IS_SCIENTIFIC_NOTATION_PATTERN = re.compile(
-    '[-+]?(\\.[0-9]+|[0-9]+(\\.[0-9]*)?)([eE][-+]?[0-9]+)'
+    '[-+]?(\\.[0-9]+|[0-9]+(\\.[0-9]*)?)([eE][-+]?[0-9]+)$'
 )
-IS_INF_PATTERN = re.compile('[-+]?(\\.inf|\\.Inf|\\.INF)')
-IS_NAN_PATTERN = re.compile('\\.nan|\\.NaN|\\.NAN')
+IS_INF_PATTERN = re.compile('[-+]?(\\.inf|\\.Inf|\\.INF)$')
+IS_NAN_PATTERN = re.compile('(\\.nan|\\.NaN|\\.NAN)$')
 
 
 def check(conf, token, prev, next, nextnext, context):