b4df304b47
For a long time now, the diff logic has relied on the behavior of `mapstructure.WeakDecode` to determine how various primitives are converted into strings. The `schema.DiffString` function is used for all primitive field types: TypeBool, TypeInt, TypeFloat, and TypeString. The `mapstructure` library's string representation of booleans is "0" and "1", which differs from `strconv.FormatBool`'s "false" and "true" (which is used in writing out boolean fields to the state). Because of this difference, diffs have long had the potential for cosmetically odd but semantically neutral output like: "true" => "1" "false" => "0" So long as `mapstructure.Decode` or `strconv.ParseBool` are used to interpret these strings, there's no functional problem. We had our first clear functional problem with #6005 and friends, where users noticed diffs like the above showing up unexpectedly and causing troubles when `ignore_changes` was in play. This particular bug occurs down in Terraform core's EvalIgnoreChanges. There, the diff is modified to account for ignored attributes, and special logic attempts to handle properly the situation where the ignored attribute was going to trigger a resource replacement. That logic relies on the string representations of the Old and New fields in the diff to be the same so that it filters properly. So therefore, we now get a bug when a diff includes `Old: "0", New: "false"` since the strings do not match, and `ignore_changes` is not properly handled. Here, we introduce `TypeBool`-specific normalizing into `finalizeDiff`. I spiked out a full `diffBool` function, but figuring out which pieces of `diffString` to duplicate there got hairy. This seemed like a simpler and more direct solution. Fixes #6005 (and potentially others!) |
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acctest | ||
config | ||
diff | ||
hashcode | ||
logging | ||
mutexkv | ||
pathorcontents | ||
resource | ||
schema | ||
README.md |
README.md
Helper Libraries
This folder contains helper libraries for Terraform plugins. A running joke is that this is "Terraform standard library" for plugins. The goal of the packages in this directory are to provide high-level helpers to make it easier to implement the various aspects of writing a plugin for Terraform.